Consider the following data for two variables, x and y.

x 22 24 26 30 35 40 y 12 21 33 35 40 36

a. Develop an estimated regression equation for the data of the form b0 b1x.

b. Use the results from part

(a) to test for a significant relationship between x and y.

Use α .05.

c. Develop a scatter diagram for the data. Does the scatter diagram suggest an estimated regression equation of the form b0 b1x b2x2 yˆ ? Explain.

d. Develop an estimated regression equation for the data of the form b0 b1x b2x2 .

e. Refer to part (d). Is the relationship between x, x2 , and y significant? Use α .05.

f. Predict the value of y when x 25.