# (Solution) Math 225N Week 3 Assignment Standard Deviation

Week 3 Assignment Standard Deviation

Question

The following dataset represents the salaries for all six employees at a small start-up company.

Find the mean, variance, and standard deviation for this dataset of salaries (expressed in thousands of dollars):

55, 59, 63, 67, 71, 75

Question

A company is interested to know the variation in yearly sales amount for all 5 salespeople in the company.

The dataset shown below is the sales amount sold by the 5 salespeople in the company (expressed in thousands of dollars):

40,60,65,70,80

Find the variance for this dataset.

Question

A large company is interested to know the variation in yearly sales for its salespeople. The dataset shown below is the yearly sales for a sample of 5 salespeople (expressed in thousands of dollars):

40, 60, 65, 70, 80

Find the variance for this dataset.

• Round the final answer to the nearest whole number.

Question

Which of the data sets represented by the following histograms has the smallest standard deviation?

Question

Which of the data sets represented by the following histograms has the smallest standard deviation?

30, 21, 19, 17, 16, 32, 26, 25, 19, 16

5, 11, 15, 7, 5, 9, 8, 16, 14, 11

25, 24, 28, 18, 32, 34, 34, 22, 28, 19

17, 19, 17, 18, 17, 16, 16, 16, 17, 20

9, 16, 14, 22, 20, 9, 19, 16, 21, 8

Question

Which of the data sets represented by the following histograms has the smallest standard deviation?

Question

Which of the following lists of data has the largest standard deviation?

9, 11, 13, 10, 13, 13, 13, 9, 9, 10

24, 15, 21, 23, 9, 22, 12, 21, 20, 13

15, 18, 18, 18, 18, 15, 15, 15, 16, 16

23, 24, 23, 24, 26, 25, 26, 23, 26, 24

10, 12, 13, 11, 11, 14, 14, 11, 12, 12

Question

The following data values represent the daily amount spent by a family during a 7 day summer vacation.

Find the population standard deviation of this dataset:

\$96, \$125, \$80, \$110, \$75, \$100, \$121

Question

The following data values represent the daily amount spent by a family during a 7 day summer vacation.

Find the sample standard deviation of this dataset:

\$96, \$125, \$80, \$110, \$75, \$100, \$121

• Round the final answer to one decimal place.

Question

The data below are the monthly average high temperatures for November, December, January, and February in New York City from the Country Studies/Area Handbook Series sponsored by the U.S. Department of the Army between 1986 and 1998. What is the sample standard deviation?

54,42,40,40

• Round the final answer to one decimal place.

6.7

3

45.3

136

Solution:

Question

The following dataset represents the salaries for all six employees at a small start-up company.

Find the mean, variance, and standard deviation for this dataset of salaries (expressed in thousands of dollars):

55, 59, 63, 67, 71, 75

Mean = 65.0, Standard Deviation = 6.8, Variance = 46.7

Question

A company is interested to know the variation in yearly sales amount for all 5 salespeople in the company.

The dataset shown below is the sales amount sold by the 5 salespeople in the company (expressed in thousands of dollars):

40,60,65,70,80

Find the variance for this dataset.

Answer= 176(Note the difference between this question & the next one)

Question

A large company is interested to know the variation in yearly sales for its salespeople. The dataset shown below is the yearly sales for a sample of 5 salespeople (expressed in thousands of dollars):

40, 60, 65, 70, 80

Find the variance for this dataset.

• Round the final answer to the nearest whole number.