Please answer the questions that you are sure about !!!

1) The diameter of DVDs is normally distributed with the population mean of 3.5 cm. Periodically, quality control inspectors at Dandenong DVDs randomly select a sample of 16 DVDs. If the mean diameter of the DVDs is too large or too small, the DVD punch is shut down for adjustment; otherwise, the punching process continues. The last sample showed a mean and standard deviation of 3.49 and 0.08 cm, respectively. Using = 0.05, the appropriate decision is _______.

Select one:

a. do not reject the null hypothesis and do not shut down the punch

b. reject the null hypothesis and do not shut down the punch

c. reject the null hypothesis and shut down the punch

d. do not reject the null hypothesis and shut down the punch

2) Consider the following null and alternative hypotheses.

These hypotheses indicate a one-tailed test with a rejection area in the left tail.

Select one:

a. False

b. True

3) A researcher has a theory that the average age of managers in a particular industry is over 35-years-old, and he wishes to prove this. The null hypothesis to conduct a statistical test on this theory would be ____________.

Select one:

a. the population mean = 35

b. the population mean >35

c. the population mean

d. the population mean

4) Restaurateur Daniel Valentine is evaluating the feasibility of opening a restaurant in Richmond. The Chamber of Commerce estimates that 'Richmond families, on the average, dine out at least 3 evenings per week'. Daniel plans to test this hypothesis at the 0.01 level of significance using a random sample of 81 Richmond families. The critical z-value is __________.

Select one:

a. -2.58

b. 2.58

c. 2.33

d. -2.33

5) When a true null hypothesis is rejected, the researcher has made a _______.

Select one:

a. Type I error

b. powerful error

c. sampling error

d. Type II error

6) Whenever hypotheses are established such that the alternative hypothesis is >, then this would be a _______.

Select one:

a. two-tailed test

b. Type II test

c. Type I test

d. one-tailed test

7) Consider the following null and alternative hypotheses.

These hypotheses _______________.

Select one:

a. are not collectively exhaustive

b. are not mutually exclusive

c. are established correctly

d. do not reference a population parameter

8) The probability of committing a Type I error is called _______.

Select one:

a. the level of significance

b. beta

c.the power of the test

d. reliability

9) In performing a hypothesis test where the null hypothesis is that the population mean is 6.9 against the alternative hypothesis that the population mean is not equal to 6.9, a random sample of 16 items is selected. The sample mean is 7.1 and the sample standard deviation is 2.4. It can be assumed that the population is normally distributed. The level of significance is selected as 0.05. The table 't' value for this problem is _______.

Select one:

a. 1.753

b. 2.131

c. 2.947

d. 2.120

10) Hypothesis testing is derived from the mathematical notion of indirect proof.

Select one:

a. True

b. False

11) Consider the following null and alternative hypotheses.

These hypotheses _______________.

Select one:

a. are established incorrectly

b. indicate a two-tailed test

c. indicate a one-tailed test with a rejection area in the right tail

d. indicate a one-tailed test with a rejection area in the left tail

12) When the rod shearing process at Newcastle Steel is 'in control' it produces rods with a mean length of 120 cm. Periodically, quality control inspectors select a random sample of 36 rods. If the mean length of sampled rods is too long or too short, the shearing process is shut down. The last sample showed a mean of 120.2 cm. The population standard deviation is 1.2 cm. Using =0.05, the appropriate decision is _________.

Select one:

a. reject the null hypothesis and do not shut down the process

b. do not reject the null hypothesis and shut down the process

c.reject the null hypothesis and shut down the process

d. do not reject the null hypothesis and do not shut down the process

13) Jennifer Cantu, Customer Services Manager at Tri-Nation Auto Insurance, monitors the processing time of the claims division. Each week, her staff randomly selects a sample of 60 claims and tests the null hypothesis that the 'mean processing time is 5 days or less'. Jennifer chooses a 0.05 level of significance, the critical z-value is _____.

Select one:

a. 1.96

b. -1.96

c. -1.645

d. 1.645

14) The first step in testing a hypothesis is to establish _______.

Select one:

a. an indirect hypothesis

b. a power function

c. a not rejectance hypothesis and a rejection hypothesis

d. a null hypothesis and alternative hypothesis

15) Jennifer Cantu, Customer Services Manager at Tri-Nation Auto Insurance, monitors the processing time of the claims division. Each week, her staff randomly selects a sample of 64 claims and tests the null hypothesis that the 'mean processing time is 5 days or less' using a 0.05 level of significance. Last week the sample mean was 5.2 days. Assuming a population standard deviation of 1.56 days, the appropriate decision is _____.

Select one:

a.increase the sample size

b. reject the null hypothesis

c. reduce the sample size

d. do not reject the null hypothesis