A car company wants to know the monthly sales made in ($000), based on the brand of vehicle. The data collected was entered on a MINITAB spreadsheet for analysis. Exhibit II below was subsequently...

A car company wants to know the monthly sales made in ($000), based on the brand of vehicle.  The data collected was entered on a MINITAB spreadsheet for analysis. Exhibit II below was  subsequently generated.
                                                     Exhibit 2

d) Assuming normality, construct and interpret a 90% confidence interval for the average  monthly earning from Toyota Vehicles.
e) You are required to test at the 5% level of significance the hypothesis that the average  monthly earnings on Hyundai Vehicles is equal to $110,000 versus the alternative that it is  different from $110,000.
Complete the following:
i. Give the null and alternative hypothesis of this test.
ii. Determine the critical value(s) of this test.
iii. Compute the value of the test statistic.
iv. State the decision rule.
v. Give your decision based on the available sample evidence.
vi. Hence, state your conclusion.