Please circle your answer to the following questions (1 point each). 1. When a random sample is selected from a population, the sample mean is not expected to be exactly equal to the population mean. What value measures the average size of the difference between a sample mean and the population mean? a. the standard error b. the mean of the population c. the standard deviation of the population d. the expected value 2. A hypothesis test is a. a descriptive technique that allows researchers to describe a sample b. a descriptive technique that allows researchers to describe a population c. an inferential technique that uses sample data to draw inferences about a population d. an inferential technique that uses population data to draw inferences about a sample 3. As alpha level increases (moves 'om .05 to .07) what happens to the risk of a Type I error? a. It increases b. It decreases. c. It stay the same. 4. In a sampling distribution when a sample reaches the size of 30 a. the distribution shape is skewed b. the distribution shape doesn't change c. the distribution shape is almost normal Questions 5 and 6: a. What are the null and alternative hypotheses? (1 pt) b. What are the degrees of freedom and the critical value? (1/2 pt) c. Calculate the statistic show all your work. (2 pts for #5, 4 pts for #6) d. What is the statistical decision (reject or fail) and what is the study conclusion? (1 pt.) 5. A researcher is testing the effect of a new cold and u medication on reaction time. A sample of n=l6 students is obtained and each student is given the normal dose of the medicine. Thirty minutes later, each student's reaction time is measured. The scores for the sample averaged 220 milliseconds with a standard deviation of 20. Asspgripdgjhat reaction time for students in the regular population averages 200 milliseconds, are the data sufficient to conclude that the medication has a signicant effect on reaction time? Use a two-tailed one-group t-test with alpha = .05. 6. After taking a preparatory college reading course, a sample of high school students takes a reading comprehension test. Their scores are listed below. If the mean for the general population on this test is 12, can you conclude that the preparatory course worked? Test using a one-tailed (directional), one-group t-test with alpha = .05. Scores: 16, 8, 8, 6, 9, 11, 13, 9, 10