51. Refer to Example 12.12 in which x volume fraction of oxides/inclusions and y % elongation. a. MINITAB gave s 0 1(.40)

51. Refer to Example 12.12 in which x
volume fraction of oxides/inclusions and y
% elongation.

a. MINITAB gave sˆ

0ˆ

1(.40)
.0311 and s
ˆ

0ˆ

1(1.20)
.0352.

Why is the former estimated standard deviation smaller than the latter one?

b. Use the MINITAB output from the example to calculate a 95% CI for expected % elongation when volume fraction
.40.

c. Use the MINITAB output to calculate a 95% PI for a single value of % elongation to be observed when volume fraction
1.20.