Stascs Test 4

11/16/17

Mulple Choice:

1. A test to screen for a minor ailment is similar to hypothesis tesng, with a null hypothesis of no sickness, and an

alternave hypothesis of sickness. If the null hypothesis is rejected treatment will be given. Otherwise, it will not.

Assuming the treatment can have very serious side effects if the paent is not sick, it is beer to increase the probability

of:

A. making a Type 1 error, providing treatment when it is not needed.

B. making a Type 1 error, not providing treatment when it is needed.

C. making a Type 2 error, providing treatment when it is not needed.

D. making a Type 2 error, not providing treatment when it is needed.

2. Which of the following null hypotheses would be tested using a chi-square goodness-of-fit test?

A.

The probabilies that a family with two children will have 2 boys, 1 boy and 1 girl, and 2 girls are ¼, ½ and

¼, respecvely.

B.

There is no relaonship between frequent cell phone use (yes, no) and ADHD diagnosis (yes, no).

C.

There is no relaonship between age and opinion on having children.

D.

The probability that a randomly selected person age 50 of older has moderate to severe hearing loss is 0.73.

3.

ANSWER: D

4.

ANSWER: B

5.

ANSWER: C

6. Which of the following is FALSE?

A.

small values of alpha minimize the risk of type I errors.

B.

the statement of the alternave hypothesis never contains an equality

C. an increase in the risk of type I error also increases the risk of a type II error

D.

the significance level of a test is equal to the probability of a type I error

Chi Square Goodness of Fit Formula:

Free Response:

For every hypothesis test be sure to clearly indicate the

type of test

, the

null and alternave hypothesis

,

clearly state the

decision

, and write a

concluding

statement

.

7. The mean lasng me of 2 compeng floor waxes is to be compared. Thirty floors are randomly assigned to test

each wax. The following table is the result. Does the data indicate that wax 1 is more effecve than wax 2? Test at a 5%

level of significance. (Assume normality)

2 samp z Test

Ho: u1=u2

Ha: u1>u2

Pvalue=0.1310

Alpha = 0.05

Fail to Reject Ho. There is insufficient evidence to show that wax 1 is more effecve than wax 2

8. A new drug is being proposed for the treatment of hair loss. Unfortunately some users in early tests of the drug have

reported the growth of trichilemmal cysts as a side effect. The FDA will reject the drug if it thinks that more than 5% of

the populaon would suffer from this side effect. Out of 650 people parcipang in the drug trial, 80 of them report cyst

growth as a side effect. At 1% significance, do we have reason to believe that the FDA will reject the drug?

1 prop

Ho: p≤0.05

Ha: p>0.05

Pvalue=6.31x10

-18

Alpha = 0.01

Reject Ho. There is sufficient evidence to show that more than 5% of the populaon would suffer cysts as a

side effect. The FDA will reject the drug.