Chapter 12, Problem T12.8SPT

To determine

To find out which of the following would make the calculation in previous exercise invalid.

Answer to Problem T12.8SPT

Option (d) is the correct option.

Explanation of Solution

It is given that the good putting is more important than long driving for shooting low scores and hence winning money. To see if this is the case, then the random sample of players are selected for examining. They have assumed that the inference conditions about the slope are met and the data is calculated by the computer output is given in the question. Suppose the researcher test the hypothesis. The P-value of the test statistic is $0.0087$ . Thus, the conditions for regression inference are: Linear, Normal, Equal standard deviation and Random. Thus, by looking at the options we have,

In option (a), the calculation will still be valid, because the linear condition requires that the sample data is approximately linear.

In option (b), the calculation will still be valid because there is no condition on the distribution of the x-variable or y-variable.

In option (c), the calculation will still be valid because there is no condition on the distribution of the x-variable or y-variable.

In option (d), the calculation will no longer be valid because this violates the equal standard deviations condition as the vertical spread in the scatterplot will no longer be constant.

In option (e), the calculation will still be valid because the equal standard deviation condition refers to the residuals.

Thus, the option (d) is the correct option.