Chapter 12, Problem 81BITH

Use the following information to answer the next two exercises. The cost of a leading liquid laundry detergent in different

sizes is given in Table 12.31.

Size (ounces)	Cost ($)	Cost per ounce
16	3.99
32	4.99
64	5.99
200	10.99

Table 12.31

81.

a. Complete Table 12.31 for the cost per ounce of the different sizes.

b. Using “size” as the independent variable and “cost per ounce” as the dependent variable, draw a scatter plot of

the data.

c. Does it appear from inspection that there is a relationship between the variables? Why or why not?

d. Calculate the least-squares line. Put the equation in the form of: $\hat{y}\text{=}a+bx$

e. Find the correlation coefficient. Is it significant?

f. If the laundry detergent were sold in a 40-ounce size, find the estimated cost per ounce.

g. If the laundry detergent were sold in a 90-ounce size, find the estimated cost per ounce.

h. Does it appear that a line is the best way to fit the data? Why or why not?

i. Are there any outliers in the the data?

j. Is the least-squares line valid for predicting what a 300-ounce size of the laundry detergent would cost per ounce?

Why or why not?

k. What is the slope of the least-squares (best-fit) line? Interpret the slope.