Module 3 – Case

FREQUENCY DISTRIBUTIONS

Case Assignment

By submitting this assignment, you affirm that it contains all original work, you affirm that you have not engaged in direct duplication, copy/pasting, sharing assignments, collaboration with others, contract cheating and/or obtaining answers online help, paraphrasing, or submitting/facilitating the submission of prior work. Work found to be unoriginal and in violation of this policy is subject to consequences such as a failing grade on the assignment, a failing grade in the course, and/or elevated academic sanctions. You affirm that the assignment was completed individually, and all work presented is your own.

Problems need to include all required steps and answer(s) for full credit. All answers need to be reduced to lowest terms where possible.

Answer the following problems showing your work and explaining (or analyzing) your results. Submit your work in a typed Microsoft Word document.

The final exam scores listed below are from one section of MATH 200. How many scores were within one standard deviation of the mean? How many scores were within two standard deviations of the mean?

99 34 86 57 73 85 91 93 46 96 88 79 68 85 89

The scores for math test #3 were normally distributed. If 15 students had a mean score of 74.8% and a standard deviation of 7.57, how many students scored above an 85%?

If you know the standard deviation, how do you find the variance?

To get the best deal on a stereo system, Louis called 8 out of 20 appliance stores in his neighborhood and asked for the cost of a specific model. Below is the sample data set of prices he collected:

$216 $135 $281 $189 $218 $193 $299 $235

Find the standard deviation.

The Company collected a sample of the salaries of its employees. There are 70 salary data points summarized in the frequency distribution below:

Salary Number of Employees

5,001–10,000 8

10,001–15,000 12

15,001–20,000 20

20,001–25,000 17

25,001–30,000 13

Find the standard deviation.

Find the variance.

6. Calculate the mean and variance of the sample data set provided below. Show and explain your steps. Round to the nearest tenth.

14, 16, 7, 9, 11, 13, 8, 10

Create a frequency distribution table for the number of times a number was rolled on a die. (It may be helpful to print or write out all of the numbers so none are excluded.)

3, 5, 1, 6, 1, 2, 2, 6, 3, 4, 5, 1, 1, 3, 4, 2, 1, 6, 5, 3, 4, 2, 1, 3, 2, 4, 6, 5, 3, 1

Answer the following questions using the frequency distribution table you created in No. 7.

Which number(s) had the highest frequency?

How many times did a number of 4 or greater get thrown?

How many times was an odd number thrown?

How many times did a number greater than or equal to 2 and less than or equal to 5 get thrown?

The wait times (in seconds) for fast food service at two burger companies were recorded for quality assurance. Using the sample data below, find the following for each sample:

Range

Standard deviation

Variance

Lastly, compare the two sets of results.

Company Wait times in seconds

Big Burger Company 105 67 78 120 175 115 120 59

The Cheesy Burger 133 124 200 79 101 147 118 125

What does it mean if a graph is normally distributed? What percent of values fall within 1, 2, and 3, standard deviations from the mean?