1. You are interested in knowing whether training on implicit bias will decrease the number of use of force incidents that police departments experience. You take a sample of police departments and track their number of use of force incidents during the 30 days before the training and the 30 days after the training. Below are the results:

Before Training	After Training
1	2
21	15
11	9
16	15
76	55
24	20
91	100
21	20

Formulate a research hypothesis, a null hypothesis and test the null at the .01 level of significance by hand. Write a paragraph that outlines your hypothesis, your main findings, and what you conclude about your research.

3. What would the critical value of t be in question #1, if you tested the null at .05? Is it larger or smaller? Why?

4. You are interested in knowing if calls for domestic disputes increased in police beats in the week following the shelter in place order in Atlanta following the Covid-19 outbreak. You collect data from police beats the week before the shelter in place order and the week after. The data are collected from the same police beats. You test your null hypothesis at a .01 level of significance using excel. Below are your findings.

t-Test: Paired Two Sample for Means
	Before	After
Mean	35.00	38.14
Variance	776.67	803.48
Observations	7.00	7.00
Pearson Correlation	0.98
Hypothesized Mean Difference	0.00
df	6.00
t Stat	-1.37
P(T<=t) one-tail	0.11
t Critical one-tail	3.14
P(T<=t) two-tail	0.22
t Critical two-tail	3.71

1. Write a null and research hypothesis in symbols.

1. What is the mean number of domestic dispute calls before the shelter in place order?

1. What is the sample size? How do you know?

1. Circle the t critical value that you would use to compare the calculated value of t to.

1. Using the p value from the table, can you reject your null hypothesis? How do you do?

1. Using the t critical value and t calculated value from the table, can you reject your null hypothesis? How do you do?