Question

In Exercises 14.12-14.21, we repeat the data and provide the sample regression equations for Exercises 4.48 -4.57.

a. Determine the standand error of the estimate.

b. Construct a residual plot.

c. Construct a normal probability plot of the residuals.

Short answer

$\text{The standard error of the estimate}\approx 2.45\text{.}$

Step-by-step solution

Part a) Step 1 Given Information

Part a Step 2 Explanation

From the above Analysis of variance printout,

We have $\mathrm{SSE}=6$

df=n-1

=3-2

=1

The formula for the standard error of the estimate is given by.

$s_e=\sqrt{\frac{SSE}{n-2}}$

$=\sqrt{\frac{6}{1}}$

=2.45

$\text{Therefore, the standard error of the estimate}\approx 2.45\text{.}$

Part b Step 1 Given Information

Part b Step 2 Explanation

MINITAB procedure: Step 1: Choose Stat > Regression > Regression.

Step 2: In Response, enter the column Low.

Step 3: In Predictors, enter the columns High.

Step 4: In Graphs, enter the columns High under Residuals versus the variables

Step 5: Click OK.

MINITAB output:

Hence the residual plot is drawn.

Part c Step 1 Given Information

Part c Step 2 Explanation

MINITAB procedure: Step 1: Choose Stat > Regression > Regression.

Step 2: In Response, enter the column Low

Step 3: In Predictors, enter the columns High.

Step 4: In Graphs, select Normal probability plot of residuals.

Step 5: Click OK.

MINITAB output:

$\text{Hence, the normal probability plot of the residualsis drawn.,}$