# Question: The following data show the advertising expenses expressed as a

The following data show the advertising expenses (expressed as a percentage of total expenses) and the net operating profits (expressed as a percentage of total sales) in a random sample of six drugstores:

(a) Fit a least squares line that will enable us to predict net operating profits in terms of advertising expenses.

(b) Test the null hypothesis α = 0.8 against the alternative hypothesis α > 0.8 at the 0.01 level of significance.

(a) Fit a least squares line that will enable us to predict net operating profits in terms of advertising expenses.

(b) Test the null hypothesis α = 0.8 against the alternative hypothesis α > 0.8 at the 0.01 level of significance.

## Answer to relevant Questions

With reference to Exercise 14.42, use the theory of Exercise 14.22 to construct a 95% confidence interval for a. In exercise Use the result of part(b) of exercise 14.20 to show that Is a value of a random variable having ...Redo Exercise 14.61 when the dosage is 20 milligrams. Note the greatly increased width of the confidence limits for the expected number of deaths and of the limits of prediction. This example illustrates that extrapolation, ...Use the formula of Exercise 14.29 to calculate a 95% confidence interval for β for the numbers of hours studied and the test scores on page 388 and compare this interval with the one obtained in Example 14.6. (a) Use an appropriate computer program to obtain the sample correlation coefficient for the data of Exercise 14.64. (b) Test whether this coefficient is significant using the 0.10 level. (a) Fit a linear surface to the following data: (b) How good a fit is obtained? (c) Plot the residuals against and determine whether the pattern is “random.” (d) Check for multicollinearity among the independent ...Post your question