Answer:
The 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).
Step-by-step explanation:
The (1 - <em>α</em>)% confidence interval for the difference between population means is:
The information provided is as follows:
The critical value of <em>z</em> for 98% confidence level is,
Compute the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 as follows:
Thus, the 98% confidence interval for the true difference between testing averages for students using Method 1 and students using Method 2 is (-8.04, 0.84).