Question

An experiment on memory was performed, in which 16 subjects were randomly assigned to one of two groups, called "Sentences" or "Intentional". Each subject was given a list of 50 words. Subjects in the "Sentences" group were told to form multiple sentences, each using at least two words from the list, and to keep forming sentences until all the words were used at least once. Subjects in the "Intentional" group were told to spend five minutes memorizing as many of the 50 words as possible. Subjects from both groups were then asked to write down as many words from their lists as they could recall. We are interested in drawing inference on the difference in the population average number of words recalled for subjects in the "sentences" group vs. subjects in the "intentional" group.

The data is in the table below.

Number of words recalled "Sentences" group 35 34 33 34 35 33 34 35

"Intentional" group 26 33 36 28 29 39 27 33

(For these questions, round all numeric answers to three decimal places)

a. Enter the values for the following statistics:

xsentences =

ssentences =

xintentional =

sintentional =

(xsentences - xintentional) =

standard error of (xsentences - xintentional) =

b. Construct an approximate 95% confidence interval for μsentences - μintentional

Lower bound =

Upper bound =

e. From these results, our statistical conclusion should be: (You have two attempts at this question.)

Fail to reject H0; we have good evidence that μsentences is greater than μintentional, because the 95% CI excludes zero.

Reject H0; have good evidence that μsentences is greater than μintentional, because the 95% CI excludes zero.

Fail to reject H0; we have don't have good evidence about whether μsentences is greater or smaller than μintentional, because the 95% CI excludes zero.

Reject H0; we have don't have good evidence about whether μsentences is greater or smaller than μintentional, because the 95% CI excludes zero.

Fail to reject H0; we have good evidence that μsentences is greater than μintentional, because the 95% CI contains zero.

Reject H0; we have good evidence that μsentences is greater than μintentional, because the 95% CI contains zero.

Fail to reject H0; we have don't have good evidence about whether μsentences is greater or smaller than μintentional, because the 95% CI contains zero.

Reject H0; we have don't have good evidence about whether μsentences is greater or smaller than μintentional, because the 95% CI contains zero.

f. What type of error *might* we have made? (You have two attempts at this question.)

We might have made a Type I error, because a Type I error is failing to reject a false H0.

We might have made a Type I error, because a Type I error is failing to reject a true H0.

We might have made a Type I error, because a Type I error is rejecting a true H0.

We might have made a Type I error, because a Type I error is rejecting a false H0.

We might have made a Type II error, because a Type II error is failing to reject a false H0.

We might have made a Type II error, because a Type II error is failing to reject a true H0.

We might have made a Type II error, because a Type II error is rejecting a true H0.

We might have made a Type II error, because a Type II error is rejecting a false H0.

We might have made either a Type I or a Type II error; both are possible.

We cannot possibly have made a Type I or a Type II error; neither are possible.

Answer 1