Descriptive Statistics (77 problems)

Profits Jobs and productivity! How productive are American workers? One way to answer this question is to examine annual profits per employee. The results may change, however, from one industry group to another. This problem is based on information taken from Forbes Top Companies (edited by J. T. Davis, John Wiley Publisher).

(a) A random sample of seven automotive parts companies gave the following infor­mation about profits per employee (in thousands of dollars per employee):

The following pie chart shows various expense categories of a large company.

Find the percentage of the expenses of the company for salaries.

What is the the standard deviation of the sample {-1, -1, 0, 3, 4} ?

Calculate the standard deviation for

Find: a. mean b. variance c. standard deviation.

What is the level of measurement for these items related to the newspaper business?

a) The number of papers sold each Sunday during 2004:

b) The departments, such as editorial, advertising, sports:

c) A summary of the number of papers sold by county:

d) The number of years with the paper for each employee:

(a) The normal monthly precipitation (in inches) for August is listed for 20 different U.S. cities. Find the mean of the data.

(b) Calculate the standard deviation for the data

The U.S. Weather Bureau has provided the following infor­mation about the total annual

number of reported tornados in the United States for the years 1956 to 1975:

The number of restaurants in 12 hotels in a city are: 0, 0, 1, 1, 2, 3, 3, 3, 4, 4, 5, 7

(a) What are the mean, median and mode?

(b) What are the variance and standard deviation in this sample?

The following display shows the number of people officially living in 215 randomly selected housing units in a densely populated area.

Use the above picture to answer the following questions. You may give approximate answers.

a) In this sample, what percentage of the houses, have less than 5 people living in it?

b) In this sample, what percentage of the houses, have more than 7 people living in it?

Babe Ruth was the american league champion 12 times (during the period from 1918 - 1931). The number of home runs he hit to earn the 12 titles were

11 29 54 59 41 46

47 60 54 46 49 46

Find the mean, median, and mode of the number of home runs

Find the standard deviation of the following sample: 8, 10, 12, 4 16

Twenty-four people were asked to rate the flavor of Jane's Jams 'n' Jellies brand grape jelly, on a scale of 1 to 10. The results follow:

a) Give the five-number summary (low, Q1, median, Q3, high)

b) Calculate the IQR.

What percentage of the general U.S. population are High School Drop-Outs? The Statistical Abstract of the united states, 120^th edition, gives the percentage of high school drop-outs by state.

13 11 14 14 10 9 10 14 14 14 8 10

11 11 7 9 13 13 8 11 9 10 6 12

11 8 7 15 9 10 12 10 13 5 9 10

12 9 11 12 8 13 13 9 8 10 11 11

7 7

make a box-and-whisker plot and find the inter quartile range.

Wyoming has e dropout rate of about 7%. Into what quartile does this rate fall?

The state police, using radar, checked the speeds (in mph) of 30 passing motorists at a checkpoint. The results are listed below:

44 38 41 50 36 36 43 42 49 48

35 40 37 41 43 50 45 45 39 38

50 41 47 36 35 40 42 43 48 33

Mean ______________ Median ______________ Mode ____________

Standard deviation (S_x) (Round to two-decimal places) _________________

The following data shows the time (in minutes) taken by the 9 employees of a company to finish a job satisfaction survey.

17, 38, 46, 49, 51, 53, 58,59, 61

a) Find the mean of this data.

b) Find the median of this data.

c) You discover that the number 17 should have been 71. How does this change affect

The National Sales meeting is approaching. Each regional sales manager has to do a short presentation for the Marketing department that highlights how the consumers in their territory are different from those in the Total US. You're still working with the local regional sales manager.

1. Download the Sample Data. This file contains reports generated from AMA's (American Marketing Association) website. AMA's website provides free demographical services where one can choose from a variety of criteria and generate reports based on the U.S. Census data. This particular file contains 4 reports: Census Overview, Census Employment, Census Trend, Census Population Detail based on the entire U.S.
2. Download the Sample Data. This particular file contains 4 reports: Census Overview, Census Employment, Census Trend, Census Population Detail based on the U.S. zip code 60614.
3. Using all 4 demographic reports (Overview, Trend, Employment and Population Detail) for Total US and zip code 60614, prepare a 1 page memo explaining how your territory differs from the national profile. Feel free to note anything that you found surprising in this data.

Prepare a 5-6 slide presentation of your major findings. You may group a category of data from the Total US and zip code 60614 and create a graph to show how they differ. The presentation should have at least one graph and a headline that summarizes a key takeaway from the graph. The last page should contain at least 3 questions that you would want answered based on what you've seen in this comparison

The normal monthly precipitation (in inches) for August is listed for 20 different U.S. cities. Find the mean of the data.

What is the definition of the median for a sample? Describe how median is calculated when the number of data points in the sample is an even number? Give an example that median is less sensitive to outliers than the mean of the sample.