Answer:
6.18% of the class has an exam score of A- or higher.
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 = 80, \sigma = 6.5[/tex]
What percentage of the class has an exam score of A- or higher (defined as at least 90)?
This is 1 subtracted by the pvalue of Z when X = 90. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{90 - 80}{6.5}[/tex]
[tex]Z = 1.54[/tex]
[tex]Z = 1.54[/tex] has a pvalue of 0.9382
1 - 0.9382 = 0.0618
6.18% of the class has an exam score of A- or higher.
Which expression is equivalent to log Subscript 8 Baseline 4 a (StartFraction b minus 4 Over c Superscript 4 Baseline EndFraction)?
Answer:
[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].
Step-by-step explanation:
The given expression is
[tex]\log_84a\left(\dfrac{b-4}{c^4}\right)[/tex]
Using the properties of logarithm, we get
[tex]\log_84+\log_8a+\log_8\left(\dfrac{b-4}{c^4}\right)[/tex] [tex][\because \log_a mn=\log_a m+\log_a n][/tex]
[tex]\log_84+\log_8a+\log_8(b-4)-\log_8c^4[/tex] [tex][\because \log_a \frac{m}{n}=\log_a m-\log_a n][/tex]
[tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex] [tex][\because \log_a x^n =n\log_a x][/tex]
Therefore, the required expression is [tex]\log_84+\log_8a+\log_8(b-4)-4\log_8c[/tex].
Answer:
B on edge
Step-by-step explanation:
URGERNT!!!PLS AT LEAST TAKE A LOOK!!! SHARE YO SMARTNESSS!! AND BLESS YOUR GRADES!
Which sign explains the relationship between m∠1 and m∠2 in the diagram?
A) not equal to
B) >
C) <
D) =
Answer:
Dear Laura Ramirez
Answer to your query is provided below
Option D is correct.
Reason - Because of Hinge and Converse of Hinge theorem
A fair die is rolled twice, with outcomes X for the first roll and Y for the second roll. Find the moment generating function MX`Y ptq of X ` Y . Note that your answer should be a function of t and can contain unsimplified finite sums.
Answer:
[tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]
Step-by-step explanation:
The objective is to find the moment generating function of [tex]M_{X+Y}(t) \ of \ X+Y[/tex].
We are being informed that the fair die is rolled twice;
So; X to be the value for the first roll
Y to be the value of the second roll
The outcomes of X are: X = {1,2,3,4,5,6}
Where ;
[tex]P (X=x) = \dfrac{1}{6}[/tex]
The outcomes of Y are: y = {1,2,3,4,5,6}
Where ;
[tex]P (Y=y) = \dfrac{1}{6}[/tex]
The outcome of Z = X+Y
[tex]= \left[\begin{array}{cccccc}(1,1)&(1,2)&(1,3)&(1,4)&(1,5)&(1,6)\\ (2,1)&(2,2)&(2,3)&(2,4)&(2,5)&(2,6)\\ (3,1)&(3,2)&(3,3)&(3,4)&(3,5)&(3,6) \\ (4,1)&(4,2)&(4,3)&(4,4)&(4,5)&(4,6) \\ (5,1)&(5,2)&(5,3)&(5,4)&(5,5)&(5,6) \\ (6,1)&(6,2)&(6,3)&(6,4)&(6,5)&(6,6) \end{array}\right][/tex]
= [2,3,4,5,6,7,8,9,10,11,12]
Here;
[tex]P (Z=z) = \dfrac{1}{36}[/tex]
∴ the moment generating function [tex]M_{X+Y}(t) \ of \ X+Y[/tex]is as follows:
[tex]M_{X+Y}(t) \ of \ X+Y[/tex] = [tex]E(e^{t(X+Y)}) = E(e^{tz})[/tex]
⇒ [tex]\sum \limits^{12}_ {z=2 } et ^z \ P(Z=z)[/tex]
= [tex]\mathbf{\dfrac{e^{2t}}{36} + \dfrac{e^{3t}}{18} + \dfrac{e^{4t}}{12} +\dfrac{e^{5t}}{9} + \dfrac{5e^{6t}}{36} + \dfrac{7e^{7t}}{6} + \dfrac{5e^{8t}}{36} + \dfrac{e^{9t}}{9} + \dfrac{e^{10t}}{12} + \dfrac{e^{11t}}{18} + \dfrac{e^{12t}}{36} }[/tex]
If Romeo earns 8% more than Juliet, Romeo’s salary is how many times Juliets salary?
A) 1.08
B) 0.92
C) 80
D) 108
Answer:
1.08
Step-by-step explanation:
If Romeo earns 8% more than Juliet,
Example?
If Juliet earns $80
80x8% = 6.40 So his pay would be 80 + 6.40
If you times 80 by 1.08 (this would also be 108%) you would get $86.40
Please help me. I’ll mark you as brainliest if correct
Answer:
b = -18
Step-by-step explanation:
(3 + 4i) (-3-2i)
When we foil:
-9 + -6i + -12i + -8i^2
-8i^2 = +8
Combine like terms:
-1 + -18i
The mean height of women in a country (ages 20-29) is 64.3 inches. A random sample of 75 women in this age group is selected. What is the probability that the mean height for the sample is greater than 65 inches? Assume sigma=2.81.
Answer:
z(65) = (65-64.2)/[2.81/sqrt(60)] = 0.8/(0.3279)
Step-by-step explanation:
Using the normal probability distribution and the central limit theorem, it is found that there is a 0.0154 = 1.54% probability that the mean height for the sample is greater than 65 inches.
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. By the Central Limit Theorem, for samples of size n, the standard deviation is [tex]s = \frac{\sigma}{\sqrt{n}}[/tex]In this problem:
Mean of 64.3 inches, thus [tex]\mu = 64.3[/tex]Standard deviation of 2.81 inches, thus [tex]\sigma = 2.81[/tex]Sample of 75, thus [tex]n = 75[/tex].The probability that the mean height for the sample is greater than 65 inches is 1 subtracted by the p-value of Z when X = 65, thus:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]Z = \frac{65 - 64.3}{\frac{2.81}{\sqrt{75}}}[/tex]
[tex]Z = 2.16[/tex]
[tex]Z = 2.16[/tex] has a p-value of 0.9846.
1 - 0.9846 = 0.0154
0.0154 = 1.54% probability that the mean height for the sample is greater than 65 inches.
A similar problem is given at https://brainly.com/question/24663213
Length of a rod: Engineers on the Bay Bridge are measuring tower rods to find out if any rods have been corroded from salt water. There are rods on the east and west sides of the bridge span. One engineer plans to measure the length of an eastern rod 25 times and then calculate the average of the 25 measurements to estimate the true length of the eastern rod. A different engineer plans to measure the length of a western rod 20 times and then calculate the average of the 20 measurements to estimate the true length of the western rod.
Answer:
b. The engineer who weighed the rod 25 times.
Step-by-step explanation:
Hello!
Full text:
Length of a rod: Engineers on the Bay Bridge are measuring tower rods to find out if any rods have been corroded from salt water. There are rods on the east and west sides of the bridge span. One engineer plans to measure the length of an eastern rod 25 times and then calculate the average of the 25 measurements to estimate the true length of the eastern rod. A different engineer plans to measure the length of a western rod 20 times and then calculate the average of the 20 measurements to estimate the true length of the western rod.
Suppose the engineers construct a 90% confidence interval for the true length of their rods. Whose interval do you expect to be more precise (narrower)?
a. Both confidence intervals would be equally precise.
b. The engineer who weighed the rod 25 times.
c. The engineer who weighed the rod 20 times.
X₁: Length of an eastern rod of the Bay Bridge
n₁= 25
X₂: Length of a western rod of the Bay Bridge
n₂= 20
Both Engineers will use their samples to estimate the population average length of the rods using a 90% CI.
Assuming the standard normal distribution, the confidence interval will be centered in the estimated mean.
X[bar] ± [tex]Z_{1-\alpha /2}[/tex]*(σ/√n)
And the width is determined by the semi amplitude:
↓d= [tex]Z_{1-\alpha /2}[/tex]*(σ/√↑n)
As you can see the sample size has an indirect relationship with the semi amplitude of the interval. This means, when the sample size increases, the semi amplitude decreases, and if the sample size decreases, the semi amplitude increases. Naturally this is leaving all other elements of the equation constant, this means, using the same confidence level and the same population standard deviation.
Since the first engineer took the larger sample, he's confidence interval will be narrower and more accurate.
Hope this helps!
Mel buys a shirt that cost 12.50 and some pairs of socks that are 2.50 each.He pays a total of 27.50$.How many pairs of socks did Mel buy?
Answer:
6
Step-by-step explanation:
Let's call the number of pairs of socks he buys s.
[tex]12.50+2.50s=27.50[/tex]
Subtract 12.50 from both sides:
[tex]2.50s=15[/tex]
Divide both sides by 2.5 to isolate s:
[tex]s=6[/tex]
Hope this helps!
e
65. the perpendicular
bisector of the
segment with
endpoints (-5/2,-2)
and (3, 5)
HELP PLEASE! Picture included!
Answer:
44x +56y = 95
Step-by-step explanation:
To write the equation of the perpendicular bisector, we need to know the midpoint and we need to know the differences of the coordinates.
The midpoint is the average of the coordinate values:
((-2.5, -2) +(3, 5))/2 = (0.5, 3)/2 = (0.25, 1.5) = (h, k)
The differences of the coordinates are ...
(3, 5) -(-2.5, -2) = (3 -(-2.5), 5 -(-2)) = (5.5, 7) = (Δx, Δy)
Then the perpendicular bisector equation can be written ...
Δx(x -h) +Δy(y -k) = 0
5.5(x -0.25) +7(y -1.5) = 0
5.5x -1.375 +7y -10.5 = 0
Multiplying by 8 and subtracting the constant, we get ...
44x +56y = 95 . . . . equation of the perpendicular bisector
What sequence is generated by the function f(n+1)=f(n)-2 for f(1)=10
Answer:
-3
Step-by-step explanation:
Which are steps that could be used to solve 0 = 9(x2 + 6x) – 18 by completing the square? Check all that apply. 18 + 81 = 9(x2 + 6x + 9) 18 + 9 = 9(x2 + 6x + 9) 18 + 36 = 9(x2 + 6x + 36) 11 = (x + 3)2 StartRoot 342 EndRoot = (x + 6)2 StartRoot 99 EndRoot = (x + 3)2
Answer:
18 + 81 = 9(x² + 6x + 9)
11 = (x + 3)²
When we are completing the square, we are going to move the value of c across the equals. We will do that by adding, and end up with
18=9(x²+6x)
We take the value of b (the coefficient of x), divide it by 2 and square it:
(6/2)²=3²=9
This is the value that completes the square. However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:
18+9(9) = 9(x²+6x+9)
18+81=9(x²+6x+9)
99=9(x²+6x+9)
Dividing both sides by 9, we have:
11=x²+6x+9
11=(x+3)²
Answer:
18 + 81 = 9(x2 + 6x + 9) and 11 = (x + 3)2
Step-by-step explanation:
EDG
What measures of the cylinder do 12 and 42 describe?
A cylinder with height of 42 millimeters and radius of 12 millimeters.
radius and diameter
radius and height
diameter and height
diameter and area of base
Answer: radius and height
Step-by-step explanation:
Radius is the distance between the center of the circle to its boundary.
Height is the length of the figure from top to bottom.
Given statement : A cylinder with height of 42 millimeters and radius of 12 millimeters.
That clearly means that the cylinder is having radius of 12 millimeters i.e. 12 is representing the measure of the radius of the cylinder.
And Similarly, 42 is representing the measure of the height of the cylinder.
Hence, the 2 and 42 describe the radius and height respectively of the cylinder.
Answer:
radius and height
Step-by-step explanation:
i just took the test edge 2020. rate me 5 stars!
Find the value of z
Answer:
87°
Step-by-step explanation:
In the given figure, a quadrilateral is inscribed in a circle. Therefore, it is a cyclic quadrilateral.
Opposite angles of a cyclic quadrilateral are supplementary.
[tex] \therefore \: z + 93 \degree = 180 \degree \\ \therefore \: z = 180 \degree - 93 \degree \\ \huge \red{ \boxed{\therefore \: z = 87 \degree}}[/tex]
When converting measurements in the metric system, you can move the decimal point to the left or to the right. Why? Select all that apply. A. When converting from smaller to larger units, you are dividing by a power of 10. B. Moving a decimal point is the same as adding or subtracting. C. The metric system is based on powers of 10. D. When converting from larger to smaller units, you are multiplying by a power of 10.
Answer:
This has multiple answers, A, C, And D
Step-by-step explanation:
Answer:
It is definitely A, C, and D.
Step-by-step explanation:
I just answered this question and got it right. I hope this helps and please mark brainliest!
For circle O, and m∠ABC = 55°. In the figure, ∠ and ∠ have measures equal to 35°.
Answer:
In the figure ∠ABO and ∠BCO have measures equal to 35°.
Step-by-step explanation:
Measure of arc AD = 180-measure of arc CD= 180-125 =55
m<AOB= 55 ( measure of central angle is equal to intercepted arc)
<OAB= 90 degrees (Tangent makes an angle of 90 degrees with the radius)
In triangle AOB ,
< AB0 = 180-(90+55)= 35 degrees( angle sum property of triangle)
In triange BOC ,< BOC=125 ,
m<, BCO=35 degrees
Answer:
∠ABO and ∠BCO
Step-by-step explanation:
Which letter has at least one line of symmetry?
W
Z
S
F
Answer:
Both F and Z have symmetry.
Help me please the questions are in the picture!!! THX MARK U AS BRAINIEST
Answer:
D is 10
b/12
Step-by-step explanation:
Any help would be great
Answer:
30%
Step-by-step explanation:
fat ÷ total
15 ÷ 50
.3
30%
Answer:
30%
Step-by-step explanation:
To find the percent from fat, take the calories from fat and divide by the total
15/50
.3
Multiply by 100%
30%
resuelve las siguientes ecuaciones tales que 0° ≤ x ≤ 360°
sen x=sen (π/2-x)
cos x + 2 sen x= 2
csc x = sec x
2 cos x * tan x -1 = 0
4 cos2 x = 3 - 4 cos x
Answer:
4cos=2X
X=3-4COS
X=-1
Claim: The mean pulse rate (in beats per minute) of adult males is equal to 69.3 bpm. For a random sample of 140 adult males, the mean pulse rate is 69.8 bpm and the standard deviation is 11.2 bpm. Complete parts (a) and (b) below.
a. Express the original claim in symbolic form.
_,_,bpm
Answer:
Part a
Null hypothesis: [tex] \mu = 69.3[/tex]
Alternative hypothesis: [tex]\mu \neq 69.3[/tex]
Part b
[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]
Step-by-step explanation:
For this case we have the following info given :
[tex] \bar X = 69.8[/tex] the sample mean
[tex] n= 140[/tex] represent the sample size
[tex] s = 11.2[/tex] represent the standard deviation
Part a
And we want to test if the true mean is equal to 69.3 so then the system of hypothesis:
Null hypothesis: [tex] \mu = 69.3[/tex]
Alternative hypothesis: [tex]\mu \neq 69.3[/tex]
Part b: Find the statistic
The statistic is given by:
[tex] z= \frac{\bar X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
And replacing the info we got:
[tex] z = \frac{69.8- 69.3}{\frac{11.2}{\sqrt{140}}}= 0.528[/tex]
simplify : 3/5x+x , find the answer ?
Answer:
8x/5
There’s a 1 in front of the x also remember to always simplify
3/5x + 1x
Answer:8x/5
Step-by-step explanation:
Assume a simple random sample of 10 BMIs with a standard deviation of 1.186 is selected from a normally distributed population of recent Miss America winners. Use 0.01 significance level to test the claim that the BMI for recent Miss America winners are from a population with standard deviation of 1.34.
A. Identify the null hypothesis and the alternative hypothesis.
B. Find the critical value or values.
C. Find the test statistic.
D. State the conclusion that addresses the original claim.
Answer:
a) H0: [tex]\sigma = 1.34[/tex]
H1: [tex]\sigma \neq 1.34[/tex]
b) [tex] df = n-1= 10-1=9[/tex]
And the critical values with [tex]\alpha/2=0.005[/tex] on each tail are:
[tex] \chi_{\alpha/2}= 1.735, \chi_{1-\alpha/2}= 23.589[/tex]
c) [tex] t=(10-1) [\frac{1.186}{1.34}]^2 =7.05[/tex]
d) For this case since the critical value is not higher or lower than the critical values we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not significantly different from 1.34
Step-by-step explanation:
Information provided
n = 10 sample size
s= 1.186 the sample deviation
[tex]\sigma_o =1.34[/tex] the value that we want to test
[tex]p_v [/tex] represent the p value for the test
t represent the statistic (chi square test)
[tex]\alpha=0.01[/tex] significance level
Part a
On this case we want to test if the true deviation is 1,34 or no, so the system of hypothesis are:
H0: [tex]\sigma = 1.34[/tex]
H1: [tex]\sigma \neq 1.34[/tex]
The statistic is given by:
[tex] t=(n-1) [\frac{s}{\sigma_o}]^2 [/tex]
Part b
The degrees of freedom are given by:
[tex] df = n-1= 10-1=9[/tex]
And the critical values with [tex]\alpha/2=0.005[/tex] on each tail are:
[tex] \chi_{\alpha/2}= 1.735, \chi_{1-\alpha/2}= 23.589[/tex]
Part c
Replacing the info we got:
[tex] t=(10-1) [\frac{1.186}{1.34}]^2 =7.05[/tex]
Part d
For this case since the critical value is not higher or lower than the critical values we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not significantly different from 1.34
Sabrina has designed a rectangular painting that measures 65 feet in length and 30 feet in width. Alfred has also designed a rectangular painting, but it measures x feet shorter on each side. When x = 3, what is the area of Alfred's painting?
Answer:
1674 ft²
Step-by-step explanation:
Area S = 65*30
Area A = (65 - x)(30 - x) = (65 - 3)(30 - 3) = 62*27= 1674 ft²
YOU KNOW THE DRILL 2.0
Answer:
#1
Step-by-step explanation:
The four yellow boxes represent x so together they are 4 * x or 4x. The blue boxes seem to represent -1 and since there are three of them together they are -1 * 3 = -3. 4x + (-3) = 4x - 3.
Avantraveling 20 miles per hour can stop in 60 feet. If a van is traveling 32 miles per hour what is it’s stopping distance
At the beginning of the week, Josh had 32 computer games, 133% as many computer games than Peter had. By the end of the week, Josh gave Peter 25% of his computer games. How many computer games did Josh and Peter each have bythe end of the week?
a. Josh had 8 games; Peter had 24 games.
b. Josh had 24 games; Peter had 8 games.
c. Josh had 24 games; Peter had 32 games.
d. Josh had 32 games; Peter had 24 games.
Answer:
The correct answer is letter c. Josh had 24 games and Peter had 32 by the end of the week.
Step-by-step explanation:
We know that Josh has a total of 32 games, while that value is 133% as many as Peter's, therefore the number of games Peter had at the beginning of the week is:
[tex]josh = \frac{133}{100}*peter\\peter = \frac{josh}{1.33}\\peter = \frac{32}{1.33}\\peter = 24.06[/tex]
At the beginning of the week Peter had 24 games. At the end of the week Josh gave Peter 25% of his games, therefore Peter's total is:
[tex]peter = 24 + 0.25*josh\\peter = 24 + 0.25*32\\peter = 24 + 8 = 32[/tex]
While Josh had:
[tex]josh = 32 - 8 = 24[/tex]
The correct answer is letter c.
The temperature in a town is −2.7°C. The temperature decreases 3°C. What is the new temperature? Incorrect
Answer:
-5.7° C
Step-by-step explanation:
-2.7 °C (degrees Celsius) - 3 °C (degrees Celsius) = -5.7° C
Which statement best compares the graphs of y = –3xn and y = 3xn?
Answer: choice B
Step-by-step explanation:
The graph of y=-3x^n is the reflection of the graph of y=3x^n about the x-axis.
Answer: B
Step-by-step explanation:
Calculo el area del búmeran tomando en cuenta que su diámetro es 20 cm
Answer:
50π cm²
Step-by-step explanation:
In this case we have that the area of the boomerang has been the area of the largest semicircle minus the area of the smaller semicircles.
We know that the radius is half the diameter:
r = d / 2 = 20/2
r = 10
Now we have to:
Alargest = π · r²
Alargest = π · (10 cm) ²
Alargest = 100π cm²
Asmaller = π · r²
Asmaller = π · (5 cm) ²
Asmaller = 25π cm²
Finally, the boomerang area has been:
Aboomerang = 100π cm² - 2 · (25π cm²)
Aboomerang = 50π cm²
Q 2.20: In a survey, there are two categories of respondents, employed and unemployed people, and two options, A and B. The proportion of those who have chosen option B is greater than 0.5 among the total number of the respondents, but is lower than 0.5 among the unemployed respondents. We know that 314 employed and 512 unemployed people chose option A and 356 employed chose option B. How many unemployed people chose option B
Answer:
The answer is 508
Step-by-step explanation:
Solution
First of all, the proportion of B is exceeds 0.5 in total.
Now,
To find the total of A it we have A =314 +512 = 826
The number of employed that choose B = 356
For us to have the proportion of B to be higher than the 0.5, the unemployed B from what is shown here should exceed the difference between total A and B employed
what this suggest is that the employed B is greater than 826-356 = 470
So,
The respondent that are unemployed that choose B must be greater than 470
Thus,
We recall that the B proportion among the unemployed respondent is lesser than .50
Thus suggests that the respondent that are unemployed who choose be is lesser than 512
The conditions becomes
470 lesser than the number of unemployed respondents who selected B lesser than 512
Hence the needed number of the number of unemployed respondents who chose B should be between 470 and 512
So, possible answer here is 508.