A researcher wants to know if using videos to illustrate concepts in class improves exam scores. He uses the videos after the first exam in his course and then collects exam scores from the 62...

A researcher wants to know if using videos to illustrate concepts in class improves exam scores. He uses the videos after the first exam in his course and then collects exam scores from the 62 students in his class for the second exam. He wants to compare scores on the first exam and the second exam to see if the scores increased after he started using the videos. On average, the difference in scores between the first exam and the second exam was 5%, with a standard deviation of 8%. Use this description to answer the questions below.

a. What is the alternative hypothesis for this study?

b. What is the null hypothesis for this study?

c. What tcrit should the researcher use in this study if his α = 0.05?

d. Do the videos seem to help? Explain your answer.