1. Consider the following hypothesis tests: H0: 20 Ha: <20 The research sample was 50 and the sample mean was 19.4. The

1. Consider the following hypothesis tests:
H0: µ ≥ 20
Ha: µ <20
The research sample was 50 and the sample mean was 19.4. The standard deviation (standard deviation) is 2. (weight 50)
Question:
a. Calculate the statistical test value.
b. What is the p-value?
c. Using a = 0.05, what is your conclusion?
d. What if the rejection rule uses critical values? What's your conclusion?

2. In a study entitled How Undergraduate Students Use Credit Cards, it was reported that undergraduate students had an average credit card balance of $ 2800. This figure is an all-time high and has increased 44% from the previous five years. Define the null hypothesis and the alternatives to determine whether it can be concluded that the average credit card balance for undergraduate students has continued to increase compared to the original report. (weights 20)

3. Why is it necessary to test classical assumptions before performing multiple regression tests please explain? (weight 30)

Thank you!