A sample of students was given a diagnostic test before studying a particular statistics module, and again after completing the module. The data are as follows. Enter the values of each delta in the table below (enter WHOLE numbers here, no decimals, ie: 2, 3, -5) :

Before	After	Delta (After - Before)
18	22	?
21	25	?
16	17	?
22	24	?
19	16	?

What is the sample size n_d above?

What are the degrees of freedom, df?

What is the mean x_d? Round to one decimal place (x.x)

Test the hypothesis to determine whether studying the statistics module led to a difference in overall scores. Use an -level of 0.05.

Choose whether a 1-sided or 2-sided test:

• One-sided or Two-sided?

What are the hypothesis statements?

• H0: diff = 0 ; HA: diff 0
• H0: diff = 0 ; HA: diff < 0
• H0: diff = 0 ; HA: diff > 0
• H0: diff > 0 ; HA: diff 0

What is the standard error (SE)? Report answer to 3 decimal places (x.xxx)

What is the test statistic? Report answer to 3 decimal places (x.xxx)

Based on the t_stat, what is the p-value (use Table C)?

• 0.40 > p > 0.30
• 0.30 > p > 0.20
• 0.20 > p > 0.10
• 0.10 > p > 0.05

What conclusion do we arrive to?

• We reject the null hypothesis that the mean difference between the test scores before and after studying the statistics module is greater than zero.
• We reject the null hypothesis that the mean difference between the test scores before and after studying the statistics module is different from zero.
• We do not find enough evidence to reject the null hypothesis that the mean difference between the test scores before and after studying the statistics module is greater than zero.
• We do not find enough evidence to reject the null hypothesis that the mean difference between the test scores before and after studying the statistics module is different from zero.