Hi, may i get i help with this question please?

As I'm confused how exactly to use the data into the questions and answer them.

*note: Data table link bellow the question:

Question Use the data set assigned to you.

A study was commissioned to investigate the characteristics of employees at a major business. Data was collected on 60 employees, and the following variables were recorded.

Column 1GenderWhat is your gender?

Column 2AgeHow old are you?

Column 3SalaryWhat is your yearly salary (before tax)?

Column 4OvertimeHow much overtime do you work each week?

Column 5Job TypeWhat department do you work in?(1 = Purchasing,

2 = Marketing/Human Resources, 3 = Accounting).

(a)Calculate a 95% confidence interval for the unknown population mean amount of overtime each employee works each week.

(b)The company has been accused of gender inequality. Test, at the 5% level of significance, whether the average salary of males is greater than the average salary of females. [You may assume that the unknown population standard deviations for male and female salaries are equal].

(c)Test, at the 5% level of significance, whether Job Type of an employee is dependent on the employee's Gender.

Data link:

https://learn-ap-southeast-2-prod-fleet01-xythos.s3.ap-southeast-2.amazonaws.com/5df059da37b55/9624183?response-cache-control=private%2C%20max-age%3D21600&response-content-disposition=inline%3B%20filename%2A%3DUTF-8%27%27Data%2520-%2520Question%25203.pdf&response-content-type=application%2Fpdf&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20201006T090000Z&X-Amz-SignedHeaders=host&X-Amz-Expires=21600&X-Amz-Credential=AKIAYDKQORRYZBCCQFY5%2F20201006%2Fap-southeast-2%2Fs3%2Faws4_request&X-Amz-Signature=fe66389878b25a72312cbd478b4796e9df573c45e6ca9be13efa5fe574d1557b