According to the Glassdoor.com, each job opening on average attracted 250 rsums in 2016. You know that

According to the Glassdoor.com, each job opening on average attracted 250 résumés in 2016. You know that the job market improved in 2017 compared to 2016, which means that more people will likely be switching jobs but also fewer unemployed workers remain in the labor market. To find out which trend is stronger, you take a random sample of 20 employers in your area and ask them to report how many résumés they received in 2017 for each job opening. 

Here are their answers:

212 228 208 260 280 204 220 244 196 244
216 256 176 228 220 240 212 244 204 224

Using α = 0.05, answer the following:

a. State the null and alternative hypotheses.

b. Does this sample provide enough evidence to suggest that the number of résumés that were received in 2017 has changed?

c. Determine the precise p-value for this test using Excel.

d. What assumptions need to be made to perform this analysis?