PSY 305 St Leo University Statistics Questions
1.A professor has been teaching statistics for many years.His records show that the overall mean for final exam scores is 85 with a standard deviation of 10.He believes that this year’s class is superb to the previous classes.The mean for the 40 students is 90.
2. A researcher gives a group of participants (n = 15) a memory technique to use.He finds that they remember on average 20 words (sample standard deviation = 3) while the average number of words remembered in the population is 15.
What is the null hypothesis?What is the research hypothesis?Is this a one or two tailed hypothesis?
Calculate the appropriate statistical test.What is the critical value for ? = .05?What do you conclude?
3.What is the difference between a z-test and a t-test (i.e., when would you use each one)