I need help with these questions and I need to study them for a test can someone please help. I need these questions answer to use as a study guide. I have a test on tuesday I need to take

A sample of 25 account balances of a credit company showed an average balance of $4,450 with a standard deviation of $230.

Compute the test statistic.How do you know if you should use z or t?

Conduct a hypothesis test. Include all steps of hypothesis testing. Using the p-value approach, what is your conclusion? Let = .05.If I am using computer programs, you must go beyond running the program and providing the printout.You must pull out only the relevant information based on things like if this is a one-tail vs. two-tail test.

During the recent primary elections, the democratic presidential candidate showed the following pre-election voter support in Alabama and Mississippi.

State

Voters Surveyed

Voters in favor of Democratic Candidate

Alabama

700

400

Mississippi

900

525

I need help to determine whether or not the proportions of voters favoring the Democratic candidate were the same in both states. Conduct a full hypothesis test (all steps, p value approach) at 90% confidence.

In order to estimate the difference between the yearly incomes of marketing managers in the East and West of the United States, the following information was gathered.

East

West

n = 40

N = 42

X = $70,000

X= $71,500

S = 3000

S= 4000

Develop an interval estimate for the difference between the average yearly incomes of the marketing managers in the East and West. Use = 0.05.

At 95% confidence, conduct a full hypothesis test. Use the p-value approach to determine if the average yearly income of marketing managers in the East is significantly different from the West.