13.2. The following data are for pounds tension of piston rings before and after ferroxing as in Table 13.1, but with an inverted V bar suspension with the gaps up, first 20 rings out of 300:

x 4.3 5.4 4.9 5.5 4.8 4.4 4.5 4.8 4.9 4.4 y 4.8 5.9 5.5 6.0 5.4 5.1 5.2 5.4 5.5 4.8 x 4.3 4.6 5.0 4.4 4.8 5.9 5.3 5.7 4.8 4.9 y 4.8 5.3 5.6 6.0 5.3 6.6 6.0 6.3 5.6 5.5

a. Plot a scatter diagram and comment.

b. Find r, bo, b1, and sy.x, write the estimation equation, and draw the line on the scatter diagram.

c. Is r significant?

d. Estimate y, if x¼4.8.
For both Problems 13.3 and 13.4, for the respective variables of Table 13.2

a. Plot a scatter diagram and comment.

b. Find r, bo, b1, and sy.x write the estimation equation, and draw the line on the scatter diagram.