1.

We often feel that the return trip from a destination takes less time than the trip to the destination even though the distance traveled is usually identical. To better understand this effect, a group of researchers ran a series of experiments. In one experiment, they surveyed69participants who had just returned from a day trip by bus. Each was asked to rate how long the return trip had taken, compared with the initial trip, on an 11-point scale from -5 = a lot shorter to 5 = a lot longer. The sample mean was0.550.55and the sample standard deviation was2.15.

Is there evidence that the mean rating is different from zero? Carry out the significance test using=0.05=0.05and summarize the results

We have evidence that the mean rating is different from 0.

We does not have evidence that the mean rating is different from 0

2.

The costs of four new cellular phones are $160, $215, $99 and $195. The average and standard deviation of these costs are $167.25 and $50.86, respectively. Based on these four cellular phones the standard error of the mean is:

12.71.

50.86.

25.43.

167.25.

3.

Which of the following is an example of a matched pairs design?

A teacher compares the scores of students using a computer-based method of instruction with the scores of other students using a traditional method of instruction.

A teacher compares the scores of students in her class on a standardized test with the national average score.

A teacher calculates the average of scores of students on a pair of tests and wishes to see if this average is larger than 80%.

A teacher compares the pretest and posttest scores of students.

4.

I need to attach it.

5.

Consider a significance test for a null hypothesis versus a two-sided alternative.

Give a value ofz(0.001) that will give a result significant at the 1% level but not at the 0.5% level.

<|z|<

6.

Step 1:

Here are several situations where there is an incorrect application of the ideas presented in this section. Determine what is wrong in each situation.

A change is made that should improve student satisfaction with the way grades are processed at your college.

The null hypothesis, that there is an improvement, is tested versus the alternative, that there is no change.

The null hypothesis must include the standard deviation as well.

Since grades have no units, no hypotheses could be set here.

The null hypothesis should be no change.