QZ3_HYPO1

1.The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $20,000 annually. The alternate hypothesis is that the mean is not $20,000.

If the level of significance is 0.10, what is the decision rule?

Do not reject the null hypothesis if computed z lies between1.65 and +1.65; otherwise, reject it

Do not reject the null hypothesis if computed z is greater than 1.65; otherwise, reject it

Do not reject the null hypothesis if computed z lies between1.96 and +1.96; otherwise, reject it

Reject the null hypothesis if computed z is below style='outline: 0px;font-variant-ligatures: normal;font-variant-caps: normal; orphans: 2;text-align:start;widows: 2;-webkit-text-stroke-width: 0px; text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial; word-spacing:0px;outline: 0px;font-weight:inherit;font-style:inherit; outline: 0px;font-weight:inherit;font-style:inherit;outline: 0px;font-weight: inherit;font-style:inherit id="mc-ans-_506246212_1_0" style="font-family: inherit; text-shadow: none !important; letter-spacing: normal !important; font-weight: inherit; font-style: inherit; font-size: 14px; vertical-align: middle;"' alt=Picture v:shapes="_x0000_i1027">1.96; otherwise, reject it

This is two tailed test.

Critical value at 0.10 level = -1.645 , 1.645

Decision rule =Reject H0 if z < -1.645 or z > 1.645

A

2.The null hypothesis

Is a statement about the value of the population parameter.

Will always contain the equal sign.

Cannot include values less than 0.

Both a and b are correct.

D

3.Which of the following statements are correct when deciding whether to use thezor thetdistribution?

Usezwhen the sample size is 30 or more.

Usezwhen we have a normal population and we know the standard deviation.

Usetwhen the population is normal, the population standard deviation is not known, andnis less than 30.

All of the above statements are correct.

D

4.The mean weight of newborn infants at a community hospital is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds.

If= 0.05, what is the critical t value?

2.365

1.96

style='outline: 0px;font-variant-ligatures: normal;font-variant-caps: normal; orphans: 2;text-align:start;widows: 2;-webkit-text-stroke-width: 0px; text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial; word-spacing:0px;outline: 0px;font-weight:inherit;font-style:inherit; outline: 0px;font-weight:inherit;font-style:inherit;outline: 0px;font-weight: inherit;font-style:inherit id="mc-ans-_506246214_1_0" style="font-family: inherit; text-shadow: none !important; letter-spacing: normal !important; font-weight: inherit; font-style: inherit; font-size: 14px; vertical-align: middle;"' alt=Picture v:shapes="_x0000_i1043">2.365

2.447

style='outline: 0px;font-variant-ligatures: normal;font-variant-caps: normal; orphans: 2;text-align:start;widows: 2;-webkit-text-stroke-width: 0px; text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial; word-spacing:0px;outline: 0px;font-weight:inherit;font-style:inherit; outline: 0px;font-weight:inherit;font-style:inherit;outline: 0px;font-weight: inherit;font-style:inherit id="mc-ans-_506246218_1_0" style="font-family: inherit; text-shadow: none !important; letter-spacing: normal !important; font-weight: inherit; font-style: inherit; font-size: 14px; vertical-align: middle;"' alt=Picture v:shapes="_x0000_i1045">2.447

D

5.What is the critical value for a one-tailed hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample size of 25?

1.708

1.711

2.060

2.064

Level of Significance , =0.05

degree of freedom=DF=n-1=24

critical t value, t*=1.711[Excel formula =t.inv.rt(,df) ]

answer: B. 1.711

B

6.A Type I error is

The correct decision

A value determined from the test statistic

Rejecting the null hypothesis when it is true

Accepting the null hypothesis when it is false.

C

7.Ap-value is

The same as the population proportion.

The same as the significance level.

The fraction of the population that has a particular characteristic.

The probability of finding a value of the test statistic this extreme when the null hypothesis is true.

A

8.The average cost of tuition, room and board at small private liberal arts colleges is reported to be $8,500 per term, but a financial administrator believes that the average cost is higher. A study conducted using 350 small liberal arts colleges showed that the average cost per term is $8,745 with a standard deviation of $1,200. Let = 0.05.

What is the test statistic for this test?

+- 3.82

0.204

-3.82

+3.82

D

9.The alternate hypothesis

Is accepted if the null hypothesis is rejected.

Will always contain the equal sign.

Tells the value of the sample mean.

None of the above.

A

10.The level of significance

Is frequently .05 or .01

Can be any value between 0 and 1.

Is the likelihood of rejecting the null hypothesis when it is true.

All of the above.

D

11.In a one-tailed test

The rejection region is in one of the tails.

The rejection region is split between the tails.

Thep-value is always less than the significance level.

Thep-value is always more than the significance level.

A

12.A Type II error occurs when

We accept a false null hypothesis.

We reject a true alternate hypothesis.

We reject a false null hypothesis.

None of the above.

A

13.The critical value is

Calculated from sample information.

Cannot be negative.

The point that divides the acceptance region from the rejection region.

A value determined from the test statistic.

D

14.To conduct a one sample test of means and use thezdistribution as the test statistic

We need to know the population mean.

We can use the sample standard deviation providednis at least 30.

We neednto be at least 5.

Both a and b are correct.

D

15.It is claimed that in a bushel of peaches less than ten percent are defective. A sample of 400 peaches is examined and 50 are found to be defective.

If= 0.025, what will be the decision?

Fail to reject the null and conclude the defects are not greater than 10%

Reject the null and conclude the defects are not greater than 10%

Reject the null and conclude the defects are greater than 10%

Fail to reject the null and conclude the defects are not less than 10%

D

16.Ifa= 0.05 for a two-tailed test, how large is the acceptance area?

0.050

0.025

0.950

0.975

C