Question 4

A researcher is interested in whether people are able to identify emotions correctly when they are extremely tired. It is known that, using a particular method of measurement, the accuracy ratings of people in the general population (who are not extremely tired) are normally distributed with a mean of 82 and a variance of 20. In the present study, the researcher arranges to test 50 people who had not slept the previous night. The researcher predicts that these people will have different accuracy than the general population, but does not predict a direction. The mean accuracy for these 50 individuals was a 78. Using the .05 level of significance, what should the researcher conclude?Use the five steps of hypothesis testing. Then, figure the confidence limits for the 95% confidence interval.Finally, write your answer as you would for a journal article using APA style.

HYPOTHESIS TESTING

Restate the question as a research hypothesis and a null hypothesis about the populations.

Determine the characteristics of the comparison distribution.

Determine the cutoff sample score (or critical value) on the comparison distribution at which the null hypothesis should be rejected.

Determine your sample's score on the comparison distribution.

Decide whether to reject the null hypothesis.

BONUS:What is the 95% confidence interval?