Week 6 Assignment

1. At a local tennis match, a player served. Let's say that the ball really was in bounds; however, the referee signaled that it was out of bounds.

a. Is this an example of a false positive or a false negative? Why?

b. Is this a type I or a type II error? Why?

2. Explain what a p-value is, and explain how it is used to test a hypothesis. Make sure to include alpha in your answer and explain what to do if p values are greater/less than alpha).

** In your discussion, you were asked to fully explain the steps of hypothesis testing. This might be a good time to get those.

3. Which of the following is a correct way of presenting a null hypothesis? Select ALL that apply. Explain why the others were incorrect.

A. Ho: p = 27

B. u : > -62

C. Ha: p = 0.92

D. Ho: 12

E. Ho: u < 16

4. Work through this hypothesis test using the prompts below. In other words, finish the sentences I have started.

A sample of 24 account balances of credit company showed a mean of customer balance of $2588, but the marketing manager claimed that the mean balance for the population was $2600. The marketing manager did not have the population standard deviation, but the sample standard deviation was $50. Use the p-value approach to conduct a full hypothesis test (all steps) that can be used to determine whether the mean of all account balances is significantly different from $2600. Let= .10.

To help you go through the steps of hypothesis testing, follow these prompts:

The null hypothesis is

The alternative hypothesis is

This test is (choose 1: one-tailed / two-tailed) because the last sentence contains the words (choose 1: greater than/ less than / different from).

I will use a (choose 1: t/z) in my formula because

I have calculated the value of t (or z) to be

(Insert your work for calculating t or z)

I have used t (or z) to get the value of p (most likely from a chart or computer printout - provide that printout). My p value is

Alpha, which is given in the problem, is

When I compared p to alpha, p is (choose 1: greater than/less than) alpha.

Because of this, I know I should (choose 1: reject / fail to reject) my null hypothesis.

Choose one: In summary, the mean balance is different from than $2600 / In summary, the mean balance is NOT different from $2600.

5. Work through this hypothesis test using each step of hypothesis testing. You may want to borrow the prompts from the previous problem.

A sample of 313 homes for sale in ABC City showed a mean asking price of $418,000, but the city claimed that the mean asking price for the population was $416,800. The population standard deviation of all homes for sale was $4,000. Use the p-value approach to conduct a full hypothesis (all steps - follow the guidance in the last problem) that can be used to determine whether the mean asking price is significantly greater than $416,800 Let=. 0.05