1. A sample of 200 elements from a population with a known standard deviation is selected. For an interval estimation of , the proper distribution to use is the

a.

t distribution with 201 degrees of freedom.

b.

t distribution with 199 degrees of freedom.

c.

t distribution with 200 degrees of freedom.

d.

normal distribution.

2. The critical value of t for a two-tailed test with 10 degrees of freedom using = .05is

a.

2.262.

b.

1.812.

c.

2.228.

d.

1.833.

3. A juice drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of drink on an average. Any overfilling or underfilling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjusted, the correct set of hypotheses is

a.

H₀: = 12 H_a: 12.

b.

H₀: 12 H_a: > 12.

c.

H₀: < 12 H_a: 12.

d.

H₀: 12 H_a: = 12.

4. The p-value

a.

can be any negative value.

b.

must be a number between -1 and 1.

c.

must be a number between 0 and 1.

d.

can be any positive value.

5. The sum of the values of and

a.

gives the probability of taking the correct decision.

b.

is always 1.

c.

is not needed in hypothesis testing.

d.

is always .5.

6. For a given sample size in hypothesis testing,

a.

the sum of Type I and Type II errors must equal to 1.

b.

the smaller the Type I error, the larger the Type II error will be.

c.

the smaller the Type I error, the smaller the Type II error will be.

d.

Type II error will not be affected by Type I error.

7. In a lower tail hypothesis test situation, the p-value is determined to be .2. If the sample size for this test is 41, the t statistic has a value of

a.

-.851.

b.

1.303.

c.

-1.303.

d.

.851.

8. If the null hypothesis is rejected at the .05 level of significance, it will _____be rejected atthe .10 level of significance.

a.

sometimes not

b.

always not

c.

always

d.

sometimes

9. Read the z statistic from the normal distribution table and choose the correct answer.For a one-tailed test (lower tail) using = .0901, z =

a.

-1.34.

b.

-1.96.

c.

-1.645.

d.

-1.86.

10. Read the t statistic from the t distribution table and choose the correct answer.For a two-tailed test with a sample size of 20 and using = .20, t =

a.

1.337.

b.

1.341.

c.

.866.

d.

.865.

11. The average manufacturing work week in metropolitan Chattanooga was 40.2 hours last year. It is believed that the recession has led to a reduction in the average work week. To test the validity of this belief, the hypotheses are

a.

H₀: = 40.2 H_a: 40.2.

b.

H₀: > 40.2 H_a: 40.2.

c.

H₀: < 40.2 H_a: 40.2.

d.

H₀: 40.2 H_a: < 40.2.