Ch9 Review

What is the critical value for a two-tailed hypothesis test on a population mean when alpha is 5%, and the population standard deviation is known?

1.96

If you were running a small sample (e.g., n=24) two-tailed test, then the critical t-value would be ________ if alpha was chosen as 5%.

2.069

The probability that the test statistic will fall inside the region of rejection due to chance alone is equal to which of the following probabilities?

Alpha

For a given level of significance, if the sample size is increased, the power of the test will decrease.

FALSE

The larger the difference between the actual value of the population mean and the value hypothesized, the larger beta will be.

FALSE

The power of a test is the probability of rejecting the Null Hypothesis when the Null Hypothesis is really true.

FALSE

The risk of committing a Type I error is higher when the level of significance selected is 0.01, compared to a level of significance of 0.05.

FALSE

The value that separates a rejection region from a nonrejection region is called the p-value.

FALSE

For a given level of significance, if the sample size is increased, the probability of committing a Type II error will increase.

False

Which of the following statements is false?

Ho (null hypothesis) refers to a specified value of a sample statistic. Refer to Section 9.1, "Hypothesis-Testing Methodology," (p. 328).

One should reach the same conclusions in the conduct of a hypothesis test, regardless of whether one is using the critical-value approach, or the p-Value approach to hypothesis testing.

T

Alpha is the probability of committing a Type I error.

TRUE

If the null hypothesis is rejected, then one can conclude that the alternative hypothesis is supported by the observed findings.

TRUE

In testing a hypothesis, the collection and examination of the data should precede the formulation of statements for the null and alternative hypotheses.

TRUE

Researchers would like the probability of which of the following research decision outcomes to be the greatest?

Statistical Power (1.00 minus Beta)

The Z test statistic is a numerical quantity computed from the data of a sample and the hypothesized population parameter, and is used in reaching a decision on whether or not to reject the null hypothesis.

TRUE

When the sample size is increased, the statistical power of the hypothesis test (1.00 minus Beta) also increases.

TRUE

Which of the following would be an appropriate alternative hypothesis for a one-tail test?

The population proportion is less than 0.65.

If a researcher wishes to determine whether there is evidence that the mean family income in the U.S. is greater than $30,000, then:

a one-tailed test should be utilized, in which the region of rejection is in the right (upper tail).

It is possible to directly compare the results of a confidence interval estimate to the results obtained by testing a null hypothesis if:

a two-tailed test is used.

The power of a statistical test is the probability of rejecting the null hypothesis when it is _______. When you increase alpha, the power of the test will _______.

false / increase

The region of rejection for a one-tailed test is:

found in the tail that supports the alternative hypothesis.

In order to reduce the likelihood of committing a Type II error, the researcher could

increase the sample size

If an individual rejects a true null hypothesis, then she/he has:

made a Type I error.

If a p-value for a hypothesis test on a mean was given as 0.0330, and the level of significance used was 5%, then the conclusion would be to

reject the null hypothesis

Which of the following measures how close the observed sample statistic has come to the hypothesized population parameter?

test statistic

The quantity (1 - alpha) is called:

the confidence coefficient.

If the p-value is less than alpha in a one-tailed test:

the null hypothesis should be rejected.

If a one-tailed test for a proportion is being performed and the upper critical value is +2.33 and the test statistic is equal to +1.37, then:

the null hypothesis should not be rejected.

If the p-value is greater than alpha in a two-tailed test:

the null hypothesis should not be rejected.

In a hypothesis test, the probability of obtaining a value of the test statistic equal to or even more extreme than the value observed - given the null hypothesis is true - is referred to as:

the p-value.

Each of the following are true with respect to Hypothesis testing except for:

there are no exceptions, because all of the statements above are true.

A Type II error is committed when:

you fail to reject a null hypothesis that is really false.