AnswersOK-Algebra II - Sem B -CA- 35031BUnit Test

Standard Deviation Answers

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1
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Fiona recorded the number of miles she biked each day last week as shown below.4, 7, 4, 10, 5The mean is given by m = 6. Which equation shows the variance for the number of miles Fiona biked last week?

A
s squared = StartFraction (4 minus 6) squared + (7 minus 6) squared + (4 minus 6) squared + (10 minus 6) squared + (5 minus 6) squared Over 6 EndFraction
Option A
B
Sigma = StartRoot StartFraction (4 minus 6) squared + (7 minus 6) squared + (4 minus 6) squared + (10 minus 6) squared + (5 minus 6) squared Over 5 EndFraction EndRoot
Option B
C
s = StartRoot StartFraction (4 minus 6) squared + (7 minus 6) squared + (4 minus 6) squared + (10 minus 6) squared + (5 minus 6) squared Over 4 EndFraction EndRoot
Option C
D
Sigma squared = StartFraction (4 minus 6) squared + (7 minus 6) squared + (4 minus 6) squared + (10 minus 6) squared + (5 minus 6) squared Over 5 EndFraction
Option D
2
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Abby is collecting rainfall data. She finds that one value of the data set is a high-value outlier. Which statement must be true?

A
Abby will use a different formula for calculating the standard deviation.
B
The outlier will increase the standard deviation of the data set.
C
The spread of the graph of the data will not change.
D
Abby will not use the mean when calculating the standard deviation.
3

The number of cars sold at a dealership over several weeks is given below.14, 23, 31, 29, 33What is the standard deviation for this set of population data?Standard deviation:

Question illustration
A
6.9
B
12.4
C
15.4
D
47.2
4

Which formula is used to calculate the standard deviation of sample data?

A
s = StartRoot StartFraction (x 1 minus x overbar) squared + (x 2 minus x overbar) squared + ellipsis + (x n minus x overbar) squared Over n minus 1 EndFraction EndRoot.
Option A
B
sigma squared = StartFraction (x 1 minus mu) squared + (x 2 minus mu) squared + ellipsis + (x N minus mu) squared Over N EndFraction
Option B
C
Sigma = StartRoot StartFraction (x 1 minus mu) squared + (x 2 minus mu) squared + ellipsis + (x N minus mu) squared Over N EndFraction EndRoot
Option C
D
x = StartFraction (x 1 minus x overbar) squared + (x 2 minus x overbar) squared + ellipsis + (x n minus x overbar) squared Over n minus 1 EndFraction
Option D
5

A set of data has a mean of 0.5 and a standard deviation of 0.01. A data point of the set has a z-score of 2.5. What does a z-score of 2.5 mean?

A
The data point is 0.01 standard deviations away from 2.5.
B
The data point is 0.01 standard deviations away from 0.5
C
The data point is 2.5 standard deviations away from 0.01.
D
The data point is 2.5 standard deviations away from 0.5.
6

A poll worker analyzing the ages of voters found that and . What is a possible voter age that would give her zx = 1.14? Round your answer to the nearest whole number.

Question illustration
A
59
B
66
C
71
D
90
7

Yuri computes the mean and standard deviation for the sample data set 12, 14, 9, and 21. He finds the mean is 14. His steps for finding the standard deviation are below.What is the first error he made in computing the standard deviation?

Question illustration
A
Yuri failed to find the difference between each data point and the mean.
B
Yuri divided by n instead of n -1.
C
Yuri did not subtract 9 - 14 correctly.
D
Yuri failed to square -2 correctly.
8

The monthly mean salaries and standard deviations of four college students are given below.StudentMeanStandard DeviationClarissa$34512.53Abi$5988.99Kaila$81215.29Shenika$2087.67Which statement must be true?

A
The monthly salary of Shenika is less spread out than the monthly salary of Clarissa.
B
The monthly salary of Kaila is less spread out than the monthly salary of Abi.
C
The monthly salary of Abi is less spread out than the monthly salary of Shenika.
D
The monthly salary of Clarissa is less spread out than the monthly salary of Abi.
9

A scientist collected two sample sets of snowfall data. Which statistic should he use to compare the spread of the two sets of data?

A
median
B
mode
C
mean
D
standard deviation
10

The mean of a set of credit scores is and . Which credit score is within a z-score of 3.3?

Question illustration
A
634
B
640
C
720
D
750
12

The mean ages with standard deviations of four swim teams at a swim club are given below.TeamMeanStandard DeviationStars164.1Dolphins181.5Giants140.3Mackerels152.3Which statement is most likely to be true?

A
The ages of the Mackerels are the most dispersed from the team’s mean.
B
The ages of the Stars are the most dispersed from the team’s mean.
C
The ages of the Dolphins are the most dispersed from the team’s mean.
D
The ages of the Giants are the most dispersed from the team’s mean.
13

A missing data value from a set of data has a z-score of –2.1. Fred already calculated the mean and standard deviation to be and . What was the missing data value? Round the answer to the nearest whole number.

Question illustration
A
39
B
41
C
45
D
47
14

A set of data has a mean of 12 and a standard deviation of 3. A data point of the set has a z-score of 1.3. What does a z-score of 1.3 mean?

A
The data point is 1.3 standard deviations away from 3
B
The data point is 1.3 standard deviations away from 12.
C
The data point is 3 standard deviations away from 1.3.
D
The data point is 3 standard deviations away from 12.
15

The test scores of a geometry class are given below.90, 75, 72, 88, 85The teacher wants to find the variance for the class population. What is the value of the numerator of the calculation of the variance?Variance:

Question illustration
A
-160
B
-6
C
16
D
258
16

The weekly salaries of a sample of employees at the local bank are given in the table below.EmployeeWeekly SalaryAnja$245Raz$300Natalie$325Mic$465Paul$100What is the variance for the data?Variance:

Question illustration
A
118.35
B
132.32
C
14,006
D
17,507.5
17

Mrs. Rodrigues wants to compare the spread of the test scores of her two biology classes. Which statistic should she use?

A
mean
B
standard deviation
C
median
D
mode

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