For the Dataset Below, the Director of HR Is Interested

For the dataset below, the Director of HR is interested in determining if her most aggressive employees are the ones with the highest salaries. To test this, she collected weekly salary information from business records and gave an aggression survey to current employees. The test manual for the aggression survey contains normative information: worldwide, the mean score on the aggression survey is a 3.1 and the standard deviation is 1.
$\begin{array}{|c|c|}\hline \text { Weekly salary (euros) } & \text { Aggression survey } \\\hline 518 & 2 \\\hline 460 & 4 \\\hline 439 & 3 \\\hline 632 & 2 \\\hline 316 & 3 \\\hline 439 & 3 \\\hline 623 & 3 \\\hline 420 & 3 \\\hline 404 & 3 \\\hline 481 & 3\\\hline\end{array}$ a) Compute a point estimate of the Salary variable above.
b) Compute an interval estimate of the Salary variable above. Report the critical z or t used.
c) Compute a point estimate of the Survey variable above.
d) Compute an interval estimate of the Survey variable above. Report the critical z or t used.