1. Dr. Jones wishes to improve people’s memory for names. On average, people can remember the names of 5 people to whom they have recently been introduced. The population standard deviation is 2.5. The shape of the distribution is normal. After a group of 9 people take Dr. Jone’s course, they are able to remember on average 7 names of people to whom they are introduced. What is the sample mean in this problem?

2.Iana randomly selects a sample of 13 people, and gives them a treatment.  She then evaluates the evidence regarding whether her treatment had an effect.  Here's the data:
The mean for her sample is 88.  The mean for the population is 95, with a standard deviation of 14.  Assume a normal distribution for the individual scores.
The Z-test tells the reader know the number of standard errors between the sample mean and the population mean.
Calculate and report the Z-test (Round to the nearest hundredth).

3. Sally offers an workshop to improve student's g.p.a.  The national average for g.p.a. is 1.83, with a standard deviation of 0.3.  15 students take Sally's workshop, and the next semester their average g.p.a. is 2.29. Assume a normal distribution for the individual scores.  Should Sally reject the null hypothesis?
If you think Sally should retain the null hypothesis, then type in the number zero as your answer.  If you think she should reject the null hypothesis, then type in the number 1 as your answer.

4. If we reject the null hypothesis, when the null hypothesis is true, we have: 
made a Type I Error
decreased power
made a correct decision
made a Type II Error

5. If we retain the null hypothesis, when the null hypothesis is false, we have:
decreased power
made a correct decision
made a Type I error
made a Type II error

6.Jill is curious whether six year olds at her school are taller than 52 inches.  She randomly selects 25 students, and finds that their average height is 54 inches (with a standard deviation of four inches).  What type of t test should she use? 

paired samples t test
all samples t test
independent samples t test
single sample t test

7.Jill is curious whether six year olds at her school are taller than 52 inches.  She randomly selects 25 students, and finds that their average height is 54 inches (with a standard deviation of four inches).  What is the degrees of freedom for this problem? 

8.John runs an experiment with an alpha of 0.05.  He is able to reject the null.  John then runs a second experiment with an alpha of .05. 
Assume that the null hypothesis was correct both times... What probability theorem would we use to calculate the probability of incorrectly rejecting the null hypothesis twice in a row? 

Multiplication Theorem of Probability
Addition Theorem of Probability (for independent events)
Addition Theorem of Probability (for mutually exclusive events)
Multiplication Theorem of Probability (for mutually exclusive events)

9.Doug believes that college students go to the movies more often than the general population.  The population mean is 5 movies per year, with a population standard deviation of 2 movies.  The distribution is positively skewed.  Doug interviews a sample of 80 college students, and finds that the sample mean is 6 movies per year.
What statistical test should be used to analyze the data?
Z test
Pearson's r
Single Sample t Test
Spearman's rho

10.Joe sends out a survey asking several college students their college major.  Later, he sends out another survey to ask another group of college students their sex (male or female). 
Assume that these two variables are independent of each other, and that the responses for each variable are mutually exclusive.  Below are the frequency tables, showing his results for these questions.
 Washington College (First Survey) Major 	Frequency
                                   Psychology 	       17
				   Business 	        5
				   Dance 	        9
			    	   Chemistry 	        5

Washington College (Second Survey) Students' Sex 	Frequency
					     Male 	26
					     Female     23
What is the probability of randomly selecting a college student at Washington who is both Female and a Psychology major?  Round to the nearest hundredth.