The attached spreadsheet contains data on the year, experience level, and salary in U.S. dollars for random samples of 79 entry-level and 206 mid-level data science jobs from 2020-2022.
Suppose that you would like to know if the mean salary for all mid-level data science jobs is greater than the mean salary for all entry-level data science jobs.
(Show your excel formulas)
1. [4] Describe the two samples selected.
2. [4] Describe the two populations of interest.
3. [4] Describe the two parameters of interest.
4. [10] What null and alternative hypotheses should you test regarding the two parameters of interest?
5. [4+4] List the four conditions the data must satisfy in order for us to be able to compute a confidence interval AND briefly explain why each condition is satisfied.
6. [5] What is the value of the test statistic?
7. [5] What is the P-value?
8. [4] Should you reject the null hypothesis in favor of the alternative or fail to reject the null hypothesis in favor of the alternative? Test at the 0.05 significance level.
9. [2+2] Is there significant evidence to support the claim that the mean salary for all mid-level data science jobs is greater than the mean salary for all entry-level data science jobs? Explain your reasoning below.
