Problem 8 Page 93:
Use StatTools to complete this problem.
Complete A, B, C.
Problem 8: The file P02_07.xlsx includes data on 204 employees at the (fictional) company Beta Technologies. Find the mean, median, and standard deviation of Annual Salary, broken down by each of the following categories. Comment on your findings.
a. Gender
b. A recoded version of Education, with new values 1
for Education less than 4, 2 for Education equal to
4, and 3 for Education greater than 4
c. A recoded version of Age, with people aged less
than 34 listed as Young, those aged at least 34 and less than 50 listed as Middle-aged, and those aged at least 50 listed as Older.
Problem 11 Page 93:
Use StatTools to complete this problem.
Complete A, B, C.
Problem 11:The file P02_35.xlsx contains data from a survey of 500 randomly selected households.
a. Create a new column Has Second Income with values “Yes” and “No” depending on whether the household has a reported second income.
b. Find the mean, median, and standard deviation of First Income, broken down by the variable you created in part a. Is there any indication that first income tends to be any larger or smaller, or has more or less variation, depending on whether there is a second income?
c. Repeat part b for each of the Monthly Payment and Debt variables.
Problem 16 Page 94:
Use StatTools to complete this problem.
Complete A, and create box plots for the two ratio variables, show outliers.
Problem 16: The file P02_11.xlsx contains data on 148 houses that were recently sold in a (fictional) suburban com- munity. The data set includes the selling price of each house, along with its appraised value, square footage, number of bedrooms, and number of bathrooms.
a. Create two new variables, Ratio 1 and Ratio 2. Ratio 1 is the ratio of Appraised Value to Selling Price, and Ratio 2 is the ratio of Selling Price to Square Feet. Identify any obvious outliers in these two Ratio variables.
Problem 22 Page 105:
Use StatTools to complete this problem.
Complete A, B, C.
Problem 22: The file P03_22.xlsx lists financial data on movies released from 1980 to 2011 with budgets of at least $20 million.
a. Reduce the size of this data set by deleting all movies with a budget of more than $100 million. Also, delete all movies where US Gross and/or Worldwide Gross is listed as Unknown.
b. For the remaining movies, create a table of correlations between the variables Budget, US Gross, and Worldwide Gross. Comment on the results. Are there any surprises?
c. For the movies remaining after part a, create a scatterplot of Worldwide Gross (Y axis) versus US Gross and another scatterplot of US Gross (Y axis) versus Budget. Briefly explain any patterns you see in these scatterplots. Do they seem to be consistent with the corresponding correlations?
Problem 30 Page 107:
Use StatTools to complete this problem
Complete A, B. C.
Problem 30: The file P03_30.xlsx contains daily data on exchange rates of various currencies versus the U.S. dollar. It is of interest to financial analysts and economists to see whether exchange rates move together through time. You could find the correlations between the exchange rates themselves, but it is often more useful with time series data to check for correlations between differences from day to day.
a. Create a column of differences for each currency.
b. Create a table of correlations between all of the original variables. Then on the same sheet, create a second table of correlations between the difference variables. On this same sheet, enter two cutoff values, one positive such as 0.6 and one negative such as −0.5, and use conditional formatting to color all correlations (in both tables) above the positive cutoff green and all correlations below the negative cutoff red. Do it so that the 1’s on the diagonal are not colored.
c. Based on the second table and your coloring, can you conclude that these currencies tend to move together in the same direction? If not, what can you conclude?
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