Question: Testing for a Linear Correlation. In Exercises 13-28, construct a scatterplot, find the value of the linear correlation coefficient r and find the critical values of r from Table A-6 using a = 0.05. Determine whether there is sufficient evidence to support a claim of a linear correlation between the two variables. (Save your work because the same data sets will be used in Section 10-3 exercises).

CPI and Pizza. The paired values of the Consumer Price Index (CPI) and the cost of a slice of pizza from Table 10-1 in the Chapter Problem are listed below. Is there a linear correlation between the CPI and the cost of a slice of pizza?