ois 2340 ch. 9

Choosing an alpha of 0.01 will cause beta to equal 0.99. True False

f

Hypothesis testing and confidence interval estimation are essentially two totally different statistical procedures and share little in common with each other. True False

f

In a two-tailed hypothesis test the area in each tail of the rejection region is equal to α. True False

f

In conducting a hypothesis test where the conclusion is to reject the null hypothesis, then either a correct decision has been made or else a Type I error. True False

t

In hypothesis testing, the null hypothesis should contain the equality sign. True False

t

A hypothesis test is to be conducted using an alpha = .05 level. This means: there is a maximum 5 percent chance that a true null hypothesis will be rejected. there is a 5 percent chance that the null hypothesis is true. there is a 5 percent chance that a Type II error has been committed. there is a 5 percent chance that the alternative hypothesis is true.

1

The manager of an online shop wants to determine whether the mean length of calling time of its customers is significantly more than 3 minutes. A random sample of 100 customers was taken. The average length of calling time in the sample was 3.1 minutes with a standard deviation of 0.5 minutes. At a 0.05 level of significance, it can be concluded that the mean of the population is: significantly less than 3. significantly greater than 3. not significantly greater than 3. not significantly different from 3.10.

2

When someone is on trial for suspicion of committing a crime, the hypotheses are: H0 : innocent HA : guilty Which of the following is correct? Type II error is convicting an innocent person. Type I error is convicting an innocent person. Type I error is acquitting a guilty person. Type II error is acquitting an innocent person.

2

If the p value is less than α in a two-tailed test, 1.a one-tailed test should be used. 2.the null hypothesis should not be rejected. 3.the null hypothesis should be rejected. 4.More information is needed to reach a conclusion about the null hypothesis.

3

Which of the following statements is true? Alpha and beta are directly related such that when one is increased the other will increase also. The alternative hypothesis should contain the equality. The decision maker controls the probability of making a Type I statistical error. Alpha represents the probability of making a Type II error.

3

The power of a test is measured by its capability of: rejecting a null hypothesis that is true. not rejecting a null hypothesis that is false. not rejecting a null hypothesis that is true. rejecting a null hypothesis that is false.

4

The Adams Shoe Company believes that the mean size for men's shoes is now more than 10 inches. To test this, it has selected a random sample of n = 100 men. Assuming that the test is to be conducted using a .05 level of significance, a p-value of .07 would lead the company to conclude that its belief is correct. True False

f

The following is an appropriate statement of the null and alternate hypotheses for a test of a population mean: H0: μ < 50 HA : μ > 50 True False

f

The null and alternate hypotheses must be opposites of each other. True False

t

To calculate beta requires making a "what if" assumption about the true population parameter, where the "what-if" value is one that would cause the null hypothesis to be false. True False

t

When the decision maker has control over the null and alternative hypotheses, the alternative hypotheses should be the "research" hypothesis. True False

t