Answer:
10 and 2
Step-by-step explanation
Nitesh is currently 10 and Ravi is currently 2
(2 times 5 is 10)
in 2 years Nitesh will be 12 and Ravi will be 4
(4 times 3 is 12)
Which chart is good for showing the following? For each part, choose the most appropriate chart from the charts listed. - trends over time - cross tabulation - the relationship among 3 quantitative variables - the relationship between 2 quantitative variables - frequency distribution of quantitative data - show differences in numbers across categories A. column or bar chart B. line chart C. heat map D. clustered column or bar chart E. bubble chart F. scatter chart G. histogram
Answer:
Step-by-step explanation:
Trends over time - Line charts
Cross tabulation - column or bar chart
The relationship among 3 quantitative variables - Bubble charts or clusteréd column or bar chart
The relationship between 2 quantitative variables - scatter plot
Frequency distribution of quantitative data - Histogram
Show differences in numbers across categories - Bar chart or column charts.
The lengths of pregnancies in a small rural village are normally distributed with a mean of 267 days and a standard deviation of 15 days. A distribution of values is normal with a mean of 267 and a standard deviation of 15. What percentage of pregnancies last beyond 246 days? P(X > 246 days) =
Answer:
91.92% of pregnancies last beyond 246 days
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 267, \sigma = 15[/tex]
What percentage of pregnancies last beyond 246 days?
We have to find 1 subtracted by the pvalue of Z when X = 246. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{246 - 267}{15}[/tex]
[tex]Z = -1.4[/tex]
[tex]Z = -1.4[/tex] has a pvalue of 0.0808
1 - 0.0808 = 0.9192
91.92% of pregnancies last beyond 246 days
Which expression converts 100 inches per minute to feet per minute?
O
100 inches
1 minute
60 minutes
1 hour
O
100 inches
1 minute
X
1 hour
60 minutes
100 inches
1 minute
X
1 foot
12 inches
O
100 inches
1 minute
12 inches
1 foot
Another question lol take your time
Answer:
100 inches Over 1 minute times × 1 foot Over 12 inches
Step by Step explanation
Remember that
1ft=12in
The expression converts 100 inches per minute to feet per minute is
100 inch / min x 1 ft/ 12 inch.
What is unit conversion?The same attribute is expressed using a unit conversion, but in a different unit of measurement. Time can be expressed in minutes rather than hours, and distance can be expressed in miles, kilometres, feet, or any other measurement unit.
We know
1 feet = 12 inch
We have to convert 100 inches per minute to feet per minute.
So, 100 inches
= 100 inch / min x 1 ft/ 12 inch
= 8.33 ft per minute
Learn more about Unit conversion here:
https://brainly.in/question/15169259
#SPJ2
A fair spinner has 11 equal sections: 3 red, 4 blue and 4 green. It is spun twice. What is the probability of getting the same colour twice?
Answer:
The probability of getting the same colour twice is approximately 34%.
Step-by-step explanation:
The probability of getting each color is:
P(x=red) = 3/11 P(x=blue) = 4/11P(x=green) = 4/11Then, we can calculate the probability of getting the color red twice as:
[tex]P(x_1=R;x_2=R)=P(x=R)^2=(3/11)^2=9/121[/tex]
We have to repeat this for the color blue and green:
[tex]P(x_1=B;x_2=B)=P(x=B)^2=(4/11)^2=16/121\\\\P(x_1=G;x_2=G)=P(x=G)^2=(4/11)^2=16/121[/tex]
Then, the probability of getting the same color twice in two spins can be calculated as:
[tex]P=P(x_1=R;x_2=R)+P(x_1=B;x_2=B)+P(x_1=G;x_2=G)=\\\\P=9/121+16/121+16/121\\\\P=41/121\approx0.34[/tex]
Suppose you would like to save P9000 invested at 8% compounded quarterly for 5 years and 6 months. (Note: Round off your answer to the nearest hundredth) (a) How much would the value of her savings at the end of the term? Answer (b) How much is the interest earned by your savings? Answer
Answer:
a) 13913
b) 4913.82
Step-by-step explanation:
The compound interest formula is given by:
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per year and t is the time in years for which the money is invested or borrowed.
In this question:
Investment of 9000, so [tex]P = 9000[/tex]
Interest rate of 8%, so [tex]r = 0.08[/tex]
Compounded quarterly, so [tex]n = 4[/tex]
5 years and 6 months, that is, 5 years and half, so [tex]t = 5.5[/tex]
(a) How much would the value of her savings at the end of the term?
[tex]A(t) = P(1 + \frac{r}{n})^{nt}[/tex]
[tex]A(5.5) = 9000(1 + \frac{0.08}{4})^{4*5.5} = 13913.82[/tex]
(b) How much is the interest earned by your savings?
The amount subtracted by the principal. So
13913.82 - 9000 = 4913.82
= [70 + (-30)] + [2 + (-9)] + [0.3 + (-0.10]
Answer:
33.2
Step-by-step explanation:
70−30+2−9+0.3−0.1
=40+2−9+0.3−0.1
=40+−7+0.3−0.1
=33+0.3−0.1
=33+0.2
=33.2
Answer:
33.2
Step-by-step explanation
If we start from the left and work our way right:
70+(-30) is the same as 70-30 which would give 40
2+(-9) is the same as 2-9 which would give -7
0.3(-0.1) is the same as 0.3-0.1 which would give 0.2
now if you put them together
40-7+.2 gives 33.2
what is X:
|4x−1|=3
|x|=−4
Answer:
1
Step-by-step explanation:
The number of pieces of popcorn in a large movie theatre popcorn bucket is normally distributed, with a mean of 1610 and a standard deviation of 10. Approximately what percentage of buckets contain between 1600 and 1620 pieces of popcorn?
Answer:
A
Step-by-step explanation:
We know that in normal distribution, approximately 34% of bags will fall with in one standard deviation on one side. On both sides within the range of 1 standard deviation, 34 + 34 = 68 % of bags will fall.
Our range is:
1600 to 1620
1610 - 10 to 1610 + 10
So the answer is 1
That means, that 68% is the answer.
Answer:
The answer is A.
Step-by-step explanation:
Approximately 68%
Choose the equation for the graph
below.
a. y =
1
X-2
2
b.y =
x²–4
3
c. y =
x+2
-3
d.y=
e. y =
2x+4
1
x2+2x+1
Answer:
C
Step-by-step explanation:
Plugged into calculator
Vertical asymptotes: x=-2
Horizontal asymptotes: y=0
No oblique asymptotes
Two surveys are conducted to measure the effect of an advertising campaign for a certain brand of detergent.27 In the first survey, interviewers ask house- wives whether they use that brand of detergent. In the second, the interviewers ask to see what detergent is being used. Would you expect the two surveys to reach similar conclusions? Give your reasons.
Answer:
NO
Step-by-step explanation:
The objective of this surveys is to determine if the two surveys will reach a similar conclusion.
From the data given, we have two test surveys here:
The survey is to measure the effect of an advertising campaign for a certain brand of detergent.
Now in the first survey; interviewers ask house- wives whether they use that brand of detergent and in the second survey the interviewers ask to see what detergent is being used.
Let assume that the brand name of the detergent is KLIN ;
From this disparities of statement ; we anticipate that they will reach different conclusion. This is because; from the first survey people will either respond to the fact that they use the brand detergent (KLIN) or do not used the brand detergent. But in the second survey; when being asked to see what detergent that is being used. There are greater chance that they will bring out the detergent that is commonly used which will eventually result to the same detergent .
Two airplanes leave an airport at the same time, flying in the same direction. One plane is flying at twice the speed of the other. If after 4 hours they are 1800 km apart, find the speed of each plane.
Answer:
One plane has a speed of 450 km/h and the other has a speed of 900 km/h.
Step-by-step explanation:
I am going to say that:
The speed of the first plane is x.
The speed of the second plane is y.
One plane is flying at twice the speed of the other.
I will say that y = 2x. We could also say that x = 2y.
Two airplanes leave an airport at the same time, flying in the same direction
They fly in the same direction, so their relative speed(difference) at the end of each hour is y - x = 2x - x = x.
If after 4 hours they are 1800 km apart, find the speed of each plane
After 1 hour, they will be x km apart. After 4, 1800. So
1 hour - x km apart
4 hours - 1800 km apart
4x = 1800
x = 1800/4
x = 450
2x = 2*450 = 900
One plane has a speed of 450 km/h and the other has a speed of 900 km/h.
A teacher figures that final grades in the chemistry department are distributed as: A, 25%; B, 25%;C, 40%;D, 5%; F, 5%. At the end of a randomly selected semester, the following number of grades were recorded. Calculate the chi-square test statistic x^2 to determine if the grade distribution for the department is different than expected. Use α = 0.01.
Grade A B C D F
Number 36 42 60 14 8
a. 6.87
b. 0.6375
c. 5.25
d. 4.82
Answer:
[tex]E_{A} =0.25*160=40[/tex]
[tex]E_{B} =0.25*160=40[/tex]
[tex]E_{C} =0.4*160=64[/tex]
[tex]E_{D} =0.05*160=8[/tex]
[tex]E_{F} =0.05*160=8[/tex]
And now we can calculate the statistic:
[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]
The answer would be:
c. 5.25
Step-by-step explanation:
The observed values are given by:
A: 36
B: 42
C: 60
D: 14
E: 8
Total =160
We need to conduct a chi square test in order to check the following hypothesis:
H0: There is no difference in the proportions for the final grades
H1: There is a difference in the proportions for the final grades
The level of significance assumed for this case is [tex]\alpha=0.01[/tex]
The statistic to check the hypothesis is given by:
[tex]\chi^2 =\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}[/tex]
Now we just need to calculate the expected values with the following formula [tex]E_i = \% * total[/tex]
And the calculations are given by:
[tex]E_{A} =0.25*160=40[/tex]
[tex]E_{B} =0.25*160=40[/tex]
[tex]E_{C} =0.4*160=64[/tex]
[tex]E_{D} =0.05*160=8[/tex]
[tex]E_{F} =0.05*160=8[/tex]
And now we can calculate the statistic:
[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]
The answer would be:
c. 5.25
Now we can calculate the degrees of freedom for the statistic given by:
[tex]df=(categories-1)=(5-1)=4[/tex]
And we can calculate the p value given by:
[tex]p_v = P(\chi^2_{4} >5.25)=0.263[/tex]
The p value is higher than the significance so we have enough evidence to FAIL to reject the null hypothesis
Does a point have a one dimension length
Answer:
No.
Step-by-step explanation:
A point has no length, height or depth. It only has position.
A line has one dimensional length.
help asap, will get branliest !!
Answer:
D
Step-by-step explanation:
Lines EF and GH are already parallel. Translating them 2 units to the side without changing how far apart they are vertically means they won't intersect and will remain the same distance apart.
Answer:
D
Step-by-step explanation:
They are parallel lines
5. The value of 25sqare -24sqare
Answer:
49
Step-by-step explanation:
25²-24²
625-576
=49
use calculator lah dehh
Assume that women's heights are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches. If 90 women are randomly selected, find the probability that they have a mean height between 62.9 inches and 64.0 inches.
A. 0.7248
B. 0.0424
C. 0.1739
D. 0.9318
A random sample of 100 observations from a population with standard deviation 6868 yielded a sample mean of 113113. Complete parts a through c below. a. Test the null hypothesis that muμequals=100 against the alternative hypothesis that muμgreater than>100, using alphaαequals=0.05. Interpret the results of the test. What is the value of the test statistic?
Answer:
Null hypothesis is rejected,
test statistic= 15.76
Step-by-step explanation:
sample mean= 113,
sample standard deviation= 68
H0: mean of sample =100
Ha: mean of sample > 100
test statistic= (population mean- sample mean)/√(standard deviation/sample size)
test statistic= (113-100)/√(68/100)= 15.76
Degrees of freeedom= 100-1=99
p-value= 1.658 (from t distribution table for DF=99 and alpha=0.05)
Since p-value is smaller than test statistic, null hypothesis is rejected
The HCF of two numbers is 11, and their L.C.M is 368. If one number is 64, then the other
number is ….
Describe the rule for the sequence 2, 1, 2/3, 1/2, 2/5, 1/3, 1/7,...
Multiply 2 by 1/2 to get 1.
Multiply 1 by 2/3 to get 2/3.
Multiply 2/3 by 3/4 to get 6/12 = 1/2.
Multiply 1/2 by 4/5 to get 4/10 = 2/5.
Multiply 2/5 by 5/6 to get 10/30 = 1/3.
Multiply 1/3 by 6/7 to get 6/21 = 2/7. (I suspect there's a typo in the question.)
And so on, so that the nth term in the sequence is multiplied by n/(n + 1) to get the (n + 1)th term.
Recursively, the sequence is given by
[tex]\begin{cases}a_1=2\\a_n=\dfrac{n-1}na_{n-1}&\text{for }n>1\end{cases}[/tex]
We can solve this exactly by iterating:
[tex]a_n=\dfrac{n-1}na_{n-1}=\dfrac{n-1}n\dfrac{n-2}na_{n-1}=\dfrac{n-1}n\dfrac{n-2}{n-1}\dfrac{n-3}{n-2}a_{n-3}=\cdots[/tex]
and so on down to
[tex]a_n=\dfrac{(n-1)\cdot(n-2)\cdot(n-3)\cdot\cdots\cdot3\cdot2\cdot1}{n\cdot(n-1)\cdot(n-2)\cdot\cdots\cdot4\cdot3\cdot2}a_1[/tex]
or
[tex]a_n=\dfrac{(n-1)!}{n!}a_1[/tex]
and with lots of cancellation, we end up with
[tex]a_n=\dfrac{a_1}n=\boxed{\dfrac2n}[/tex]
Answer:
Divide 2 by n.
Step-by-step explanation:
20sin^4 x power reduction
Answer:
Step-by-step explanation:
20 sin^4x
=5(4sin^4 x)
=5(2sin²x)²
=5(1-cos 2x)²
=5(1-4cos2x+cos²(2x))
=5[1-4cos(2x)+{1+cos (4x)}/2]
=5/2[2-8cos(2x)+1+cos(4x)]
=5/2[3-8cos (2x)+cos (4x)]
Write the equation of the line. Slope = -4, passing through (- 1, 5)
Answer:
y=-4x+1
Step-by-step explanation:
You want to find the equation for a line that passes through the point (-1,5) and has a slope of -4.
First of all, remember what the equation of a line is:
y = mx+b
Where:
m is the slope, and
b is the y-intercept
To start, you know what m is; it's just the slope, which you said was -4. So you can right away fill in the equation for a line somewhat to read:
y=-4x+b.
Now, what about b, the y-intercept?
To find b, think about what your (x,y) point means:
(-1,5). When x of the line is -1, y of the line must be 5.
Because you said the line passes through this point, right?
Now, look at our line's equation so far: . b is what we want, the -4 is already set and x and y are just two "free variables" sitting there. We can plug anything we want in for x and y here, but we want the equation for the line that specfically passes through the the point (-1,5).
So, why not plug in for x the number -1 and for y the number 5? This will allow us to solve for b for the particular line that passes through the point you gave!.
(-1,5). y=mx+b or 5=-4 × -1+b, or solving for b: b=5-(-4)(-1). b=1.
The equation of line passes through the point (-1, 5) will be;
⇒ y = - 4x - 2
The equation of line in point-slope form passing through the points
(x₁ , y₁) and (x₂, y₂) with slope m is defined as;
⇒ y - y₁ = m (x - x₁)
Where, m = (y₂ - y₁) / (x₂ - x₁)
Given that;
The point on the line are (-1, 5).
And, The slope of line is,
⇒ m = - 4
Now,
Since, The equation of line passes through the point (- 1, 5).
And, Slope of the line is,
m = - 4
Thus, The equation of line with slope - 4 is,
⇒ y - 5 = - 4 (x - (-1))
⇒ y - 2 = - 4 (x + 1)
⇒ y - 2 = - 4x - 4
⇒ y = - 4x - 4 + 2
⇒ y = - 4x - 2
Learn more about the equation of line visit:
https://brainly.com/question/18831322
#SPJ1
please hurry I’ll make brainiest
The number of people at a concert can be modeled by the following
equation where p is the number of people and t is the time passed in
minutes.
P = 30(1.10) + 20
Based on the model, which of the following statements is true?
Answer:
There were 30 people attending at the start of the concert
Step-by-step explanation:
The coefficient of the value raised to an exponent in these types of functions is always the "starting" value. In your case, '30' is the coefficient, so it is the starting value. FYI: 1.10 is the rate at which the people increase, t is time passed, 20 is a constant, and P is the total number of people after the time goes by.
Answer:
There were 30 people attending at the start of the concert.
Step-by-step explanation:
30 is the coefficient, so that's your starting point, basically.
You are at a playground with a see-saw and a large merry-go-round. You put your phone on the see-saw and find it slides when it is tilted at an angle of 38 degrees. How far can you put your phone from the center of the merry-go-round (in m) when it makes one rotation every 3 s
Answer: r_max = 1.75m
Step-by-step explanation:
Below is a rather brief analysis to solving this problem.
The phone starts sliding when along incline,
when F_net = m g sin(theta) - fs_max = 0
and fs_max = us N = us m g cos(theta)
m g sin(theta) - us m g cos(theta) =
us = tan(theta) = tan38 = 0.781
On merry - go - round,
fs_max = us N = us m g
Using F = m a
fs_max = m w^2 r_max and w = 2pi / T
us m g = m (2 pi / T)^2 (r_max)
0.781 x 9.81 = (2 pi / 3)^2 (r_max)
r_max = 1.75 m
cheers i hope this helped !!
divide the following polynomials ( 9 x 4 + 3 x 3 y − 5 x 2 y 2 + x y 3 ) ÷ ( 3 x 2 + 2 x 2 y − x y 2 )
Answer:
2(-2y+9)/3+y
Step-by-step explanation:
ASAPPPPP
PICTURE BELOW
WILL HAVE MORE OF THESE
Answer: -6m-n+3
Step-by-step explanation:
The answer is -6m-n+3 because -3
times 2m is -6m and -n stays the same its outside of the parenthesis
and lastly -3 times -1 is positive 3
so answer maches up with the last one
the answer is -6m-n+3
Hope this helps :)
Answer:
-6m-n+3
Step-by-step explanation:
-3 x 2 is -6m (n stays same)
-3 x -1 is whole or positive 3
put it together and u get -6m-n+3
hope this helps
A survey showed that 82% of adults need correction (eyeglasses, contacts, surgery, etc.) for their eyesight. If 15 adults are randomly selected, find the probability that no more than 1 of them need correction for their eyesight. Is 1 a significantly low number of adults requiring eyesight correction?
Answer:
[tex] P(X \leq 1)= P(X=0) +P(X=1) [/tex]
And using the probability mass function we can find the individual probabiities
[tex]P(X=0)=(15C0)(0.82)^0 (1-0.82)^{15-0}=6.75x10^{-12}[/tex]
[tex]P(X=1)=(15C1)(0.82)^1 (1-0.82)^{15-1}=4.61x10^{-10}[/tex]
And replacing we got:
[tex] P(X \leq 1)= P(X=0) +P(X=1)= 4.68x10^{-10}[/tex]
And for this case yes we can conclude that 1 a significantly low number of adults requiring eyesight correction in a sample of 15 since the probability obtained is very near to 0
Step-by-step explanation:
Let X the random variable of interest "number of adults who need correction", on this case we now that:
[tex]X \sim Binom(n=15, p=0.82)[/tex]
The probability mass function for the Binomial distribution is given as:
[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]
Where (nCx) means combinatory and it's given by this formula:
[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]
We want to find this probability:
[tex] P(X \leq 1)= P(X=0) +P(X=1) [/tex]
And using the probability mass function we can find the individual probabiities
[tex]P(X=0)=(15C0)(0.82)^0 (1-0.82)^{15-0}=6.75x10^{-12}[/tex]
[tex]P(X=1)=(15C1)(0.82)^1 (1-0.82)^{15-1}=4.61x10^{-10}[/tex]
And replacing we got:
[tex] P(X \leq 1)= P(X=0) +P(X=1)= 4.68x10^{-10}[/tex]
And for this case yes we can conclude that 1 a significantly low number of adults requiring eyesight correction in a sample of 15 since the probability obtained is very near to 0
Which graph represents the piecewise-defined function f(x) = -1.5x + 3.5, x < 2?
4 + x, x >2
Answer:
DID IT oN EDGEN UITY
Step-by-step explanation:
The first graph correctly represents our piecewise function f(x) = - 1.5x + 3.5 for x < 2 and 4 + x for x ≥ 2.
What is a piecewise function?A function that is piecewise-defined by numerous subfunctions, each of which has a separate domain interval for which it is applicable.
Piecewise definition is more of an expression of the function than it is a property of the function.
Given a piecewise function f(x) = - 1.5x + 3.5 for x < 2 and 4 + x for x ≥ 2.
Now, strictly less or greater than will be shown as an open circle in the graph and less than or greater than equal to will be shown by a closed circle on the graph.
If we observe the first graph when x = 0, y = 3.5, and the end is represented as an open circle which is < 2 and when x ≥ 2 it is 6 and represented with a closed circle.
learn more about piecewise function here :
https://brainly.com/question/11294479
#SPJ6
A researcher conducts two studies on the effectiveness of a peer mentoring program. Self-evaluation ratings among participants before, during, and after the program were measured in both studies. In Study 1, 12 participants were observed, and in Study 2, 16 participants were observed. If Fobt = 3.42 in both studies, then in which study will the decision be to reject the null hypothesis at α= 0.05 level of significance?
Answer:
Study 2
Step-by-step explanation:
Okay, so in this question we are given the data or parameters or information Below;
=>" two studies were conducted on the effectiveness of a peer mentoring program."
=> "Self-evaluation ratings among participants before, during, and after the program were measured in both studies."
=> In Study 1, 12 participants were observed"
=> "Study 2, 16 participants were observed."
=> " If Fobt = 3.42 in both studies"
Say Vo = study 2 and V1 = study 1.
Hence, Vo: not effective.
V1 = effective.
The study in which the decision will be to reject the null hypothesis at α= 0.05 level of significance is the STUDY 2.
This is because the value of F > f-critical.
please help :( really need answer
Answer:
Options (C) and (F)
Step-by-step explanation:
Polynomial function is,
f(x) = x³ - x² - 5x - 3
Possible rational roots of the given function will be = [tex]\frac{\pm1, \pm3}{\pm1}[/tex]
By putting x = -1
f(-1) = (-1)³ - (-1)² -5(-1) - 3
= -1 - 1 + 5 - 3
= 0
Therefore, x = -1 will a root of the given function.
Now we apply synthetic division to get the other roots,
-1 | 1 -1 -5 -3
↓ -1 2 3
1 -2 -3 0
Therefore, factored form of the polynomial will be (x + 1)(x² - 2x - 3).
Now we will find the roots of (x² -2x - 3).
x² - 2x - 3 = x² - 3x + x - 3
= x(x - 3) + 1(x - 3)
= (x + 1)(x - 3)
For roots of the function, f(x) = 0
(x + 1)(x - 3) = 0
x = -1, 3
Therefore, roots of the function are x = -1, 3
Options (C) and (F) are the answers.
An urban economist is curious if the distribution in where Oregon residents live is different today than it was in 1990. She observes that today there are approximately 3,109 thousand residents in NW Oregon, 902 thousand residents in SW Oregon, 244 thousand in Central Oregon, and 102 thousand in Eastern Oregon. She knows that in 1990 the breakdown was as follows:
72.7% NW Oregon, 20.7% SW Oregon, 4.8% Central Oregon, and 2.8% Eastern Oregon.
Can she conclude that the distribution in residence is different today at a 0.05 level of significance?
a) Yes, because the p-value = .0009.
b) No, because the p-value = .0009.
c) Yes, because the p-value = .0172.
d) No, because the p-value = .0172.
Answer:
c) Yes, because the p-value = 0.0172
Step-by-step explanation:
The following table is obtained:
Categories Observed(fo) Expected (fe) (fo-fe)²/fe
NW Oregon 3109 4357*0.727=3167.539 1.082
SW Oregon 902 4357*0.207=901.899 0
Central Oregon 244 4357*0.048=209.136 5.812
Eastern Oregon 102 4357*0.028=121.996 3.277
Sum = 4357 4357 10.171
(1) Null and Alternative Hypotheses
The following null and alternative hypotheses need to be tested:
H0:p1=0.727,p2=0.207,p3=0.048,p4=0.028
Ha: Some of the population proportions differ from the values stated in the null hypothesis
This corresponds to a Chi-Square test for Goodness of Fit.
(2) Rejection Region
Based on the information provided, the significance level is α=0.05, the number of degrees of freedom is df=4−1=3, so then the rejection region for this test is R={χ2:χ2>7.815}.
(3) Test Statistics
The Chi-Squared statistic is computed as follows:
[tex]X^2=\sum^n_{i=1}\frac{(O_i-E_i)^2}{y} \\\\= 1.082+0+5.812 +3.277 = 10.171[/tex]
(4) Decision about the null hypothesis
Since it is observed that
[tex]X^2 = 10.171 > X_c^2 = 7.815[/tex]
it is then concluded that the null hypothesis is rejected.
(5) Conclusion
It is concluded that the null hypothesis H_o is rejected. Therefore, there is enough evidence to claim that some of the population proportions differ from those stated in the null hypothesis, at the α=0.05 significance level.