Resolve the following with the corresponding formulas where they apply.

It is intended to test the hypothesis that the average annual expenses on mortgages of homes purchased in Puerto Rico is $14,000. After doing a survey with 60 household families, it was found that the sample mean was $16,000 and the sample standard deviation was $3,000. If you want to achieve a 95% reliability level in the test, determine the following:

a. What is the null hypothesis?

b. What is the critical value?

c. Determine the Z value.

d. Should the hypothesis be rejected or null?

In the space provided place the related computations and the result:

Daily sales are on average $1,125 with a standard deviation of $100. Determines the probability that sales in the coming days will be:

a. Over $1,200

B. Under $1087

c. Between $1087 and $1,200