Answer:
Cases : 2623 school children , Explanatory Variable : Greenery or Vegetation around school , Response Variable : Children's Memory & attention spans , Yes causation, Observational study
Step-by-step explanation:
a) Cases refers to the people or units of population studied in the research. In this case, it is sample of 2623 school children in Barcelona
b) Explanatory variable is variable which leads to, or causes the change in other variable. In this case, it is greenery or vegetation around researched students' schools
c) Response variable is the variable which is affected due to change in independent explanatory variable. In this case, it is children's working memory & attention spans
d) Yes, the headline implies causation. As it implies cause effect relationship of greenery around children's school on their working memory & attention spans.
e) It is an observational study, as it observes the variables relationship as it is, without any specific experimental intervention.
Find the total amount of interest on a savings account if the principal is $9400 and the bank gives a rate of 6% compounded quarterly for the next 6 years.
Answer:
4037.3264$
Step-by-step explanation:
Total amount of money after 6 years:
A = P x (1 + rate)^time
= 9400 x ( 1 + (6/100)/4)^(6 x 4)
= 13437.3264$
=> Total amount of interest after 6 years:
I = A - P = 13437.3264 - 9400 = 4037.3264$
Erin had 55 stuffed bears. She took out her favorite 7 bears and then equally divided the other bears among her 3 sisters. Erin's youngest sister, Su, already had 15 stuffed bears. How many stuffed bears does Su have now?
Answer:
27 stuffed bears
Step-by-step explanation:
Erin: 55 Su: 15
Erin: 55-7=48 ( 7 will be kept for herself)
Erin and her sisters: 48/4= 12
Each sister besides Erin and Su have 12
Su: 15+12=27
Thus, Su will have 27 stuffed bears
Answer:
31 Stuffed Bears
Step-by-step explanation:
55 - 7 = 48
48 / 3 = 16
16 + 15 = 31
Sue has 31 stuffed bears
The sum of two numbers is 4 1/2. The difference is 3 1/4. Find the numbers.
Answer:
let the two number is x and y
x + y = 4 1/2 .....(i)
x - y = 3 1/4 ......(ii)
adding question (i) and (ii)
x + y = 9/2
x - y = 31/4
=> 2x = 31/4
x = 8/31
substituting the value x in equation 1
8/31 + y = 9/ 2
y = 9/2 - 8/31
y =203/62
the value of x = 8/31
y = 203/62
A foundry has been commissioned to make souvenir coins. The coins are to be made from an alloy that is 40% silver. The foundry has on hand two alloys, one with 50% silver content and one with a 25% silver content. How many kilograms of each alloy should be used to make 10 kilograms of the 40% silver alloy?
Answer:
the amount of 50% silver alloy is 6 kilograms and the amount of 25% silver alloy is (10-6)= 4 kilograms.
Step-by-step explanation:
Suppose, the weight of the alloy with 50% silver content is x kilograms.
As, the weight of the mixed alloy should be 10 kilograms, so the weight of the alloy with 25% silver content will be: kilograms
The percentage of silver content in the mixed alloy is 40%. So the equation will be calculated as
[tex]0.5x+0.25(10-x)=0.4\times10\\0.5x+2.5-0.25x=4\\0.25x=1.5\\\Rightarrow x=\frac{1.5}{0.25} = 6[/tex]
So, the amount of 50% silver alloy is 6 kilograms and the amount of 25% silver alloy is (10-6)= 4 kilograms.
help solve the above equation
Answer:
[tex]\dfrac{1}{27}[/tex]
Step-by-step explanation:
[tex]n^{-\frac{2}{3}}=9[/tex]
Rewrite:
[tex]\dfrac{1}{\sqrt[3]{n^2}}=9\\\\9\sqrt[3]{n^2}=1[/tex]
Cube both sides:
[tex]729n^2=1[/tex]
Divide both sides by 729:
[tex]n^2=\dfrac{1}{729}[/tex]
Take the square root of both sides:
[tex]n=\sqrt{\dfrac{1}{729}}=\dfrac{1}{27}[/tex]
Hope this helps!
Find the characteristic polynomial and the eigenvalues of the matrix. [Start 2 By 2 Matrix 1st Row 1st Column 11 2nd Column 2 2nd Row 1st Column 2 2nd Column 11 EndMatrix ]The characteristic polynomial is nothing.
Answer:
Step-by-step explanation:
The answer is 3x 987 colunm 2
Help me solve (b) in this quadrilateral
Answer:
b = 87°
Step-by-step explanation:
In order to answer this question, we need to utilise an important angle fact which is angles in a quadrilateral add up to 360°
Using the information we can set up an equation to find the value of b
→ Form equation
63 + 140 + 70 + b = 360
→ Simplify
273 + b = 360
→ Minus 273 from both sides isolate b
b = 87°
Answer:
Hello!
The answer is 87 degrees!
I hope I was of help! If not please let me know! Thank you!
Step-by-step explanation:
g Brian Vanecek, VP of Operations at Portland Trust Bank, is evaluating the service level provided to walk-in customers. Accordingly, his staff recorded the waiting times for 64 randomly selected walk-in customers, and determined that their mean waiting time was 15 minutes and that the standard deviation was 4 minutes. The 88% confidence interval for the population mean of waiting times is __________.
Answer:
The 88% confidence interval for the population mean of waiting times is between 7.34 minutes and 22.66 minutes.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 64 - 1 = 63
88% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 63 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.88}{2} = 0.94[/tex]. So we have T = 1.9153
The margin of error is:
M = T*s = 1.9153*4 = 7.66.
In which s is the standard deviation of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 15 - 7.66 = 7.34 minutes
The upper end of the interval is the sample mean added to M. So it is 15 + 7.66 = 22.66 minutes.
The 88% confidence interval for the population mean of waiting times is between 7.34 minutes and 22.66 minutes.
You have already a 1000 cash on your hand. You have also a 1000 cash in bank and you withdraw half of 500, so, it means you withdraw 250. Now, you have a 1000 cash on hand plus 250 that you have been withdraw from the bank, all in all you have 1250 now in your hand.
Answer: At the end, you have $750 remaining in the bank.
Step-by-step explanation:
I guess you want to know how much is left in the bank.
initially
Hand : $1000
Bank: $1000
you withdraw $250 from the bank:
Hand: $1000 + $250 = $1250
Bank: $1000 - $250 = $750
Any help would be great
Answer:
63
Step-by-step explanation: The ratio from planet A to B is 100 to 3. If an elephant weight 2100 is planet a, then we are multiplying 21 to hundred. Whatever you do on the left side you have to do it on the right side and if you multiply 21 and 3 on the right side then you get 63.
Answer:
63 pounds
Step-by-step explanation:
The ratio for Planet A to Planet B is
100 : 3
Creating a proportionality with the unknown as x
=> [tex]\frac{100}{3} = \frac{2100}{x}[/tex]
Isolating x would give
x = [tex]\frac{2100 * 3}{100}[/tex]
x = 21 × 3
x = 63 pounds
A certain manufactured product is supposed to contain 23% potassium by weight. A sample of 10 specimens of this product had an average percentage of 23.2 with a standard deviation of 0.2. If the mean percentage is found to differ from 23, the manufacturing process will be recalibrated.
a. State the appropriate null and alternate hypotheses.
b. Should the process be recalibrated? Explain.
c. Compute the P-value.
Answer:
(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 23%
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] [tex]\neq[/tex] 23%
(b) We conclude that the mean percentage is different from 23 and the manufacturing process will be re-calibrated.
(c) P-value is 0.6%.
Step-by-step explanation:
We are given that a certain manufactured product is supposed to contain 23% potassium by weight.
A sample of 10 specimens of this product had an average percentage of 23.2 with a standard deviation of 0.2.
Let [tex]\mu[/tex] = mean percentage of potassium by weight.
(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 23% {means that the mean percentage is equal to 23 and the manufacturing process will not be re-calibrated}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] [tex]\neq[/tex] 23% {means that the mean percentage is different from 23 and the manufacturing process will be re-calibrated}
The test statistics that would be used here One-sample t-test statistics as we don't know about population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }[/tex] ~ [tex]t_n_-_1[/tex]
where, [tex]\bar X[/tex] = sample mean percentage = 23.2
s = sample standard deviation = 0.2
n = sample of specimens = 10
So, the test statistics = [tex]\frac{23.2-23}{\frac{0.2}{\sqrt{10} } }[/tex] ~ [tex]t_9[/tex]
= 3.162
The value of t test statistic is 3.162.
Since, in the question we are not given with the level of significance so we assume it to be 5%. Now, at 5% significance level the t table gives critical value of -2.262 and 2.262 at 9 degree of freedom for two-tailed test.
(b) Since our test statistic doesn't lie within the range of critical values of t, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.
Therefore, we conclude that the mean percentage is different from 23 and the manufacturing process will be re-calibrated.
(c) The P-value of the test statistics is given by;
P-value = P( [tex]t_9[/tex] > 3.162) = 0.006 or 0.6%
(a) Null Hypothesis, [tex]H_o:\mu[/tex]: = 23%
Alternate Hypothesis, [tex]H_A:\mu\neq[/tex] : 23%
(b) We conclude that the mean percentage is different from 23 and the manufacturing process will be re-calibrated.
(c) P-value is 0.6%.
What is a null hypothesis?The hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.
We are given that a certain manufactured product is supposed to contain 23% potassium by weight.
A sample of 10 specimens of this product had an average percentage of 23.2 with a standard deviation of 0.2.
Let = mean percentage of potassium by weight.
(a) Null Hypothesis, [tex]H_o:\mu[/tex]: = 23% {means that the mean percentage is equal to 23 and the manufacturing process will not be re-calibrated}
Alternate Hypothesis, [tex]H_A:\mu\neq[/tex]: 23% {means that the mean percentage is different from 23 and the manufacturing process will be re-calibrated}
The test statistics that would be used here One-sample t-test statistics as we don't know about population standard deviation;
[tex]TS=\dfrac{X-\mu}{\frac{s}{\sqrt{n}}}[/tex] ~ [tex]t_{n-1}[/tex]
where, = sample mean percentage = 23.2
s = sample standard deviation = 0.2
n = sample of specimens = 10
So, the test statistics = [tex]\dfrac{23.2-23}{\frac{0.2}{\sqrt{10}}}[/tex] ~ [tex]t_g[/tex]
= 3.162
The value of t test statistic is 3.162.
Since, in the question we are not given with the level of significance so we assume it to be 5%. Now, at 5% significance level the t table gives critical value of -2.262 and 2.262 at 9 degree of freedom for two-tailed test.
(b) Since our test statistic doesn't lie within the range of critical values of t, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.
Therefore, we conclude that the mean percentage is different from 23 and the manufacturing process will be re-calibrated.
(c) The P-value of the test statistics is given by;
P-value = P( [tex]t_g[/tex] > 3.162) = 0.006 or 0.6%
Hence ,
(a) Null Hypothesis, [tex]H_o:\mu[/tex]: = 23%
Alternate Hypothesis, [tex]H_A:\mu\neq[/tex] : 23%
(b) We conclude that the mean percentage is different from 23 and the manufacturing process will be re-calibrated.
(c) P-value is 0.6%.
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Tiffany is 140 miles away from Maggie. They are traveling towards each other. If Maggie travels 5 mph faster than Tiffany and they meet after 4 hours how fast was each traveling
Answer: Tiffany 15mph, Maggie 20mph
Step-by-step explanation:
Set up the equation 4((x+5) + x) = 140. x+5 represents how many miles Maggie covered in one hour. x represents how much Tiffany traveled in one hour. 140 is the number of miles in total. 4 is the number of hours in total.
Simplify the equation.
(x+5) + x = 35 Divide both sides by 4
2x+5 = 35 Combine like terms
2x = 30 Subtract 5 from both sides
x = 15 Divide both sides by 2
Tiffany traveled 15mph, while Maggie traveled 15+5=20mph.
Excell Computers promptly shipped two servers to its biggest client. The company profits RM5,000 on each one of these big systems. The shipping worker randomly selected the system without replacement that were delivered from 15 computers in stock. The system contain 4 refurbished computer, with 11 new computers in the warehouse.
If the client gets two new computers, Excell earns RM10,000 profit. If the client gets a refurbished computer, it’s coming back for replacement and Excell must pay the RM400 shipping fee, with leaves RM9,600 profit. If both computers shipped are refurbished, consequently the client will return both and cancel the order. As a result, Excell will be out any profit and left with RM8,000 in shipping cost. Let X be a random variable for the amount of the profit earned on the order.
Answer:
$9215.24
Step-by-step explanation:
Total Number of Computers=15
Number of New=11
Number of Refurbished Computers=4
P(New)=11/15P(Refurbished)=4/15[tex]P(NN)=\frac{11}{15} \times \frac{10}{14} = \frac{11}{21}\\P(NR)=\frac{11}{15} \times \frac{4}{14} = \frac{22}{105}\\P(RN)=\frac{4}{15} \times \frac{11}{14} = \frac{22}{105}\\P(RR)=\frac{4}{15} \times \frac{3}{14} = \frac{2}{35}[/tex]
The probability of one new and one refurbished =P(NR)+P(RN)
[tex]=\frac{22}{105}+ \frac{22}{105}\\=\frac{44}{105}[/tex]
Let X be the amount of profit earned on the purchase. The probability distribution of X is given as:
[tex]\left|\begin{array}{c|c|c|c|c}$Profit(X)& NN=\$10000 &NR=\$9600& RR=-\$800\\$P(X)&\dfrac{11}{21}&\dfrac{44}{105}&\dfrac{2}{35}\end{array}\right|[/tex]
(b) Expected Profit
[tex]\text{Expected Profit}=\sum X_iP(X_i)\\=(10000 \times \dfrac{11}{21}) +(9600 \times \dfrac{44}{105}) + (-800 \times \dfrac{2}{35})\\=\$9215.24[/tex]
The average profit of the store on the order is $9215.24.
which of the following explains expressions are equivalent to - 5/6 /-1/3
Answer:
2.5
Step-by-step explanation:
(-5/6 ) / (-1/3)
multiply the numerator and denominator by the same number -3 gives:
(-5 * -3 /6 ) / (-1* -3/3)
(15/6 ) / (3/3)
(15/6 ) / 1
(15/6 )
12/6 + 3/6
2 3/6
2 1/2
2.5
Order the numbers from least to greatest based on their absolute values.
|23|, |−37|, |−6|, |18|, |−24|, |2|
Answer:
/-37/, /-24/, /-6/, /2/, /18/, /23/
11+11=4, 22+22=16, 33+33?
Sequence= 4, 16
Difference=12
16+12=28
Answer is...
33+33=28
Borland, Inc., has a profit margin of 5.6 percent on sales of $13.6 million. If the firm has debt of $6.4 million and total assets of $9.8 million, what is the firm’s ROA?
Answer:
ROA = 7.77 percent
Step-by-step explanation:
Borland, Inc., has a profit margin of 5.6 percent on sales of $13.6 million
Thus, profit = 5.6% of $13.6 million
profit = 5.6 / 100 * $13.6 million = $0.7616 million
Profit is same as net income
Formula for ROA (return on asset) = net income/ total asset
total asset as given = $9.8 million
Thus, ROA = $0.7616/ $9.8 = 0.0777
ROA in percentage = 0.0777*100 = 7.77
Thus, ROA is 7.77 percent .
Find the population mean or sample mean as indicated.
Sample: 17, 11, 8, 12, 22
Answer:
mean:12
Step-by-step explanation:
The population mean or sample mean as indicated in the given samples is 14
What is mean?A mean in math is the average of a data set, found by adding all numbers together and then dividing the sum of the numbers by the number of numbers.
Mathematically,
Mean = Sum of the observations/number of observations
Now the given sample is,
17, 11, 8, 12, 22
So, Number of sample = 5
Thus, Mean = Sum of the sample /number of sample
Mean = (17 + 11 + 8 + 12 + 22) / 5
⇒ Mean = 70/5
⇒ Mean = 14
Thus, the population mean or sample mean as indicated in the given samples is 14
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I don’t need you to explain just answer.
Answer: The answer is (x-5)^2
Ariana is a songwriter who collects royalties on her songs whenever they are played in a commercial or a movie. Arians will earn $40 every time one of her songs is played in a commercial and she will earn $110 every time one of her songs is played in a movie. Ariana earned a total of $500 in royalties on 9 commercials and movies. Write a system of equations that could be used to determine the number of commercials and the number of movies on which Arianas songs were played. Define the variables that you use to write the system.
Answer:
Commercials x = 7
Movies y = 2
Step-by-step explanation:
Let commercials = x
Let's movies = y
$40 is for commercials
$110 is for movies.
Commercials plus movies for the Year = 9
She earned total of $500
X+ y = 9..... equation 1
40x + 110y = 500.... Equation 2
Multipling equation one by 40
40x + 40y = 360
Subtracting equation one from equation 2
70y = 140
Y = 2
If y = 2
X + y = 9
X + 2 = 9
X = 9-2
X = 7
Please help me with this question!!!
Answer:
θ = ±2π/3 +2kπ . . . . . for any integer k
Step-by-step explanation:
2·cos(θ) +1 = 0
cos(θ) = -1/2 . . . . . subtract 1, divide by 2
The cosine function has the value -1/2 for θ = ±2π/3 and any integer multiple of 2π added to that.
θ = ±2π/3 +2kπ . . . . . for any integer k
use the graph of y = tan x to find the value of y = tan 0. round to the nearest tenth of necessary. if the tangent is undefined at that point, write undefined.
a. 0.4
b. 0
c. -0.4
d. 1
Step-by-step explanation:
The graph of y = tan x is shown. We need to find what y equals when x = 0 (because in y = tan 0, x is replaced with 0)
So you can either find where x = 0 on the graph, or you can take the tangent of 0 to find your answer.
The value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is 0 and this can be determined by using the given graph.
Given :
The graph of [tex]y = \tan x[/tex].
The following steps can be used to determine the value of [tex]y = \tan 0[/tex] :
Step 1 - The graph of the trigonometric function [tex]y = \tan x[/tex] is given.
Step 2 - According to the given graph, at (x = 0) the value of y is also 0.
Step 3 - So, the value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is:
[tex]y = \tan 0[/tex]
[tex]y = 0[/tex]
The value of the trigonometric function [tex]y = \tan x[/tex] at (x = 0) is 0.
For more information, refer to the link given below:
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In the United States, the mean and standard deviation of adult men's heights are 70 inches (5 feet 10 inches) and 4 inches, respectively. Suppose the American adult men's heights have a normal distribution Whe probability that a randomly chosen American man is taller than 6 feet (72 inches) is equal to:___________. (round off to fourth decimal place, use the given table)
a. 0.6853
b. 0.0062
c. 0.3085
d.0.6915
e. None of these
Answer:
[tex]P(X>72)=P(\frac{X-\mu}{\sigma}>\frac{72-\mu}{\sigma})=P(Z>\frac{72-70}{4})=P(z>0.5)[/tex]
And we can find this probability using the complement rule and the normal standard table:
[tex]P(z>0.5)=1-P(z<0.5)= 1- 0.69146= 0.3085[/tex]
And the best solution would be:
c. 0.3085
Step-by-step explanation:
For this case we can convert all the values to inches in order to standardize the solution:
[tex] 5ft * \frac{12 in}{1ft}= 60 in[/tex]
[tex] 6ft * \frac{12 in}{1ft}= 72 in[/tex]
Let X the random variable that represent the heights of US mens, and for this case we know the distribution for X is given by:
[tex]X \sim N(70,4)[/tex]
Where [tex]\mu=70[/tex] and [tex]\sigma=4[/tex]
We are interested on this probability
[tex]P(X>72)[/tex]
We can use the z score formula given by:
[tex]z=\frac{x-\mu}{\sigma}[/tex]
Using this formula we got:
[tex]P(X>72)=P(\frac{X-\mu}{\sigma}>\frac{72-\mu}{\sigma})=P(Z>\frac{72-70}{4})=P(z>0.5)[/tex]
And we can find this probability using the complement rule and the normal standard table:
[tex]P(z>0.5)=1-P(z<0.5)= 1- 0.69146= 0.3085[/tex]
And the best solution would be:
c. 0.3085
Using the normal distribution, it is found that the probability that a randomly chosen American man is taller than 6 feet (72 inches) is equal to:
c. 0.3085
In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
It measures how many standard deviations the measure is from the mean. After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.In this problem:
Mean of 70 inches, thus [tex]\mu = 70[/tex].Standard deviation of 4 inches, thus [tex]\sigma = 4[/tex].The probability of being taller than 72 inches is 1 subtracted by the p-value of Z when X = 72, thus:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{72 - 70}{4}[/tex]
[tex]Z = 0.5[/tex]
[tex]Z = 0.5[/tex] has a p-value of 0.6915.
1 - 0.6915 = 0.3085
Thus, option c.
A similar problem is given at https://brainly.com/question/24855678
A bag contains 7 red and 10 white balls. In how many ways 4 balls are selected if there are more than 2 red balls? (Please solve it using counting rule; combination rule.)
Answer:
385 ways
Step-by-step explanation:
Given;
7 red balls
10 white balls
In how many ways can 4 balls be selected if there are more than 2 red balls.
Selecting 4 balls which must contain more than 2 red balls, will be 3 red balls and 1 white ball to make it 4 in total, or all the 4 balls selected will red balls.
= 3 red balls and 1 white ball OR 4 red balls
= 7C₃ x 10C₁ + 7C₄
[tex]= \frac{7!}{4!3!} *\frac{10!}{9!1!} \ \ + \ \frac{7!}{3!4!} \\\\= (35*10) \ + \ 35\\\\= 350 \ + 35\\\\= 385 \ ways[/tex]
Therefore, there are 385 ways of selecting 4 balls, if there are more than 2 red balls.
question is attached
I apologize, I am stumped... I thought you would find either the centroid, circumcenter, or incenter of the triangle created but it didn't work quite right for me.
What’s the correct answer for this?
Answer:
C.
Step-by-step explanation:
Measure of arcURN = 270°
In radians:
270° = 270π/180
270° = 3π/2
Now
Area of sector = 1/2r²∅
= 1/2(10)²(3π/2)
= 50(3π/2)
= 75π
A cola manufacturer invited consumers to take a blind taste test. Consumers were asked to decide which of two sodas they preferred. The manufacturer was also interested in what factors played a role in taste preferences. Suppose the manufacturer wanted to test to determine if the males preferred its brand more than the females. Using the test statistic given in the printout, compute the appropriate p-value for the test.
A. 0.0340
B. 0.0171
C. 04681
D. 0.2119
Answer: B. 0.0171
Step-by-step explanation:
The question is incomplete. The complete question is:
A cola manufacturer invited consumers to take a blind taste test. Consumers were asked to decide which of two sodas they preferred. The manufacturer was also interested in what factors played a role in taste preferences. Below is a printout comparing the taste preferences of men and women.
HYPOTHESIS: PROP. X = PROP. Y
SAMPLES SELECTED FROM soda(brand1,brand2)
males (sex=0, males) (NUMBER = 115)
females (sex=1, females) (NUMBER = 56)
X = males
Y = females
SAMPLE PROPORTION OF X = 0.422018
SAMPLE SIZE OF X = 109
SAMPLE PROPORTION OF Y = 0.25
SAMPLE SIZE OF Y = 52
PROPORTION X - PROPORTION Y = 0.172018
Z = 2.11825
Suppose the manufacturer wanted to test to determine if the males preferred its brand more than the females. Using the test statistic given, for a one-sided test, compute the appropriate p-value for the test.
Solution:
Looking at the statement, "Suppose the manufacturer wanted to test to determine if the males preferred its brand more than the females", it shows that it is a right tailed test. Since the test statistic is already known, we would find the probability value for the area above the test statistic or z score from the normal distribution table. From the table,
p value = 0.983
The required p value above the z score is
1 - 0.983 = 0.0171
the appropriate p-value for the test is 0.0171
Darnell spends $100 dollars a week
eating out. His sister told him that if he
would reduce this spending by $50 a
week, he could increase his credit card
payment to $300 per month. How much
will he save if he takes his sister's advice?
ent?
How much will Darnell save by increasing
his monthly payment by $200?
Answer:
$200
$100
Step-by-step explanation:
Darnell spends $100 dollars a week, if he reduces this spending by $50 a week, he will be able to save
$50 x 4 weeks in a months = $200
This, in a month he will be able to save $200.
Increasing his credit card payment by $200 to a total of $300...
since he now spends $50 per week now,
in a month he will spend $50 x 4 weeks = $200 and be able to save $100.
Hitchhiker Snails A type of small snail is very widespread in Japan, and colonies of the snails that are genetically similar have been found very far apart. Scientists wondered how the snails could travel such long distances. A recent study1 provides the answer. Biologist Shinichiro Wada fed live snails to birds and found that of the snails were excreted live out the other end. The snails apparently are able to seal their shells shut to keep the digestive fluids from getting in.
What is the best estimate for the proportion of all snails of this type to live after being eaten by a bird?
Answer: 0.149
Step-by-step explanation:
As Scientists wondered how the snails could travel such long distances. A recent study provides the answer. Biologist Shinichiro Wada fed 174 live snails to birds and found that 26 of the snails were excreted live out the other end.
The best estimate for the proportion of all snails of this type to live after being eaten by a bird can be achieved by calculating the ratio of survival/number of eaten snails
Where the number of eaten snails = 174
The number of survivors = 26
Estimated proportion = 26/174 = 0.1494
Therefore, the best estimate for the proportion of all snails of this type to live after being eaten by a bird will be 0.149 approximately.
A recent graduate school study of a random sample of 250 US manufacturing companies determined the average financial report preparation time was 68.04 days with a standard deviation of 35.74 days. Calculate to three decimal places the 95 percent confidence interval for the mean report prep time for all US manufacturing companies. [63.001, 72.008] [63.957, 75.568] [63.505, 72.414] [61.612, 74.468] [63.612, 72.468]
Answer:
[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]
[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]
And the best option for this case would be
Step-by-step explanation:
Information given
[tex]\bar X=68.04[/tex] represent the sample mean
[tex]\mu[/tex] population mean
s=35.74 represent the sample standard deviation
n=250 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
The degrees of freedom are given by:
[tex]df=n-1=250-1=249[/tex]
The Confidence level is 0.95 or 95%, and the significance [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and the critical value for this case woud be [tex]t_{\alpha/2}=1.956[/tex]
And replacing we got:
[tex]68.04-1.959\frac{35.74}{\sqrt{250}}=63.618[/tex]
[tex]68.04+1.959\frac{35.74}{\sqrt{250}}=72.461[/tex]
And the best option for this case would be