Chapter 4, Problem AP1.18CPT

(a)

To determine

To find out what percent of the actual sales amounts do you expect to be within $\$5$ of their expected sales amount.

Answer to Problem AP1.18CPT

  $98.2\%$ .

Explanation of Solution

The coefficient of determination is:

  $r^2=98.2\%$

  $98.2\%$ of the variation in the amount of the actual sales amounts we expect to be within $\$5$ of their expected sales amount.

(b)

To determine

To find out the middle $95\%$ of residual should be between which two values.

Answer to Problem AP1.18CPT

Should be between $3\text{ and }6$ .

Explanation of Solution

You would respond to the store manager that the range of the data for shelf length is between $3\text{ and }6$ feet working outside the range of the data could be dangerous as the results are not guaranteed to hold. Especially in the case like this where having a shelf length as zero feet is wrong.