# Stats homework #3 | Statistics homework help

1.  Provide an example of a research question using matched samples. (Include numbers and notation)

2.  Provide an example of a research question using repeated measures. (Include numbers and notation)

3.  Provide an example of a research question using independent samples. (Include numbers and notation)

4.  You have obtained the number of years of education from one random sample of 38 police officers from City A and the number of years of education from a second random sample of 30 police officers from City B. The average years of education for the sample from City A is 15 years with a standard deviation of 2 years. The average years of education for the sample from City B is 14 years with a standard deviation of 2.5 years. Is there a statistically significant difference between the education levels of police officers in City A and City B?

a.  What is the correct test for this question?

b.  What are the hypotheses?

c.  Calculate the degrees of freedom.

d.  What is the cutoff(s)?

e.  Test the hypotheses.

f.  What type of error could have been made? What would it state?

5.  Does therapy reduce anxiety?  Measure anxiety levels before and after therapy One sample (same people) measured twice.

Patient    Before X1   After X2

1                40              24

2                42              30

3                36              37

4                 31             21

5                 55             32

a.  What is the correct test for this question?

b.  What are the hypotheses?

c.  Calculate the degrees of freedom.

d.  What is the cutoff(s)?

e.  Test the hypotheses.

f.  What type of error could have been made? What would it state?

6.  A professor wants to know if her introductory statistics class has a good grasp of basic math. Six students are chosen at random from the class and given a math proficiency test. The professor wants the class to be able to score above 70 on the test. The six students get scores of 62, 92, 75, 68, 83, and 95. Can the professor state that the mean score for the class on the test would be above 70?

a.  What is the correct test for this question?

b.  What are the hypotheses?

c.  Calculate the degrees of freedom.

d.  What is the cutoff(s)?

e.  Test the hypotheses.

f.  What type of error could have been made? What would it state?

7.  Researchers want to test a new anti-hunger weight loss pill. They have 10 people rate their hunger both before and after taking the pill. Does the pill do anything? Use alpha = 0.05

Before     After      Difference

9               7           2

10             6           4

7               5           2

5               4           1

7               4           3

5               6           1

9               7           2

6               5           1

8               5           3

7               7           0

a.  What is the correct test for this question?

b.  What are the hypotheses?

c.  Calculate the degrees of freedom.

d.  What is the cutoff(s)?

e.  Test the hypotheses.

f.  What type of error could have been made? What would it state?

8.  The data below represents weight loss for people on three different exercise programs.  Can we say that these exercise programs will result in equivalent weight loss?

Program A.          Program B.          Program C

2.5.                        4.8                         4.3

8.3.                        4.9                         6.2

5.3                         1.1                         5.7

9.9                         7.7                         9.1

5.1                         1.2                         7.0

a.  What is the correct test for this question?

b.  What are the hypotheses?

c.  Calculate the degrees of freedom.

d.  What is the cutoff(s)?

e.  Test the hypotheses.

f.  What type of error could have been made? What would it state?