# Question: Help Mr B the store manager in Exercises 13 77

Help Mr. B, the store manager in Exercises 13. 77 and 13. 78 (and Exercises 12.44–12.46), by analyzing the relationship between the numbers of items purchased daily and the total daily sales in the data from the first 10 months of the year.

a. Construct the scatter diagram for the data for January to October.

b. Describe the graphical evidence found and discuss the linearity. Are there any ordered pairs that appear to be different from the others?

c. What is the relationship between the number of items purchased per day and the total daily sales for the first 10 months of the year?

d. Is the slope of the regression line significant at a = 0.05?

e. Give the 95% prediction interval for the total daily sales that one would expect if the number of items purchased per day were 3000.

a. Construct the scatter diagram for the data for January to October.

b. Describe the graphical evidence found and discuss the linearity. Are there any ordered pairs that appear to be different from the others?

c. What is the relationship between the number of items purchased per day and the total daily sales for the first 10 months of the year?

d. Is the slope of the regression line significant at a = 0.05?

e. Give the 95% prediction interval for the total daily sales that one would expect if the number of items purchased per day were 3000.

**View Solution:**## Answer to relevant Questions

a. Draw a scatter diagram of the following bivariate data b. Calculate the covariance. c. Calculate sx and sy. d. Calculate r using formula (13.2). e. Calculate r using formula (13.3). A study concerning the plasma concentration of the drug ranitidine was reported in the Journal of Pharmaceutical Sciences. The drug was administered (coded I), and the plasma concentration of ranitidine was followed for 12 ...It is believed that the amount of nitrogen fertilizer used per acre has a direct effect on the amount of wheat produced. The following data show the amount of nitrogen fertilizer used per test plot and the amount of wheat ...An article titled “Graft-versus-Host Disease” (http://www.nature.com/) gives the median age of 42 years for the 87 patients with acute myeloid leukemia (AML) who received hematopoietic stem cell transplants from ...Fifty-one percent of grooms say they want to lose weight before their wedding day, according to the USA Today Snapshot “Weigh-in before the wedding.” Suppose we wish to test the hypothesis that at least one-half of ...Post your question