Multiple Choice Practice

As the test statistic becomes more extreme, the p-value a. gets smaller. b. becomes larger. c. goes beyond 1. d. becomes negative.

A. gets smaller

In the hypothesis testing procedure, α is the a. level of significance. b. critical value. c. confidence level. d. p-value.

A. level of significance

When the p-value is used for hypothesis testing, the null hypothesis is rejected if a. p-value <= α. b. α < p-value. c. p-value = 1 - α/2. d. p-value = 1 - α.

A. p-value <= α

Two approaches to drawing a conclusion in a hypothesis test are a. p-value and critical value. b. one-tailed and two-tailed. c. Type I and Type II. d. null and alternative.

A. p-value and critical value

The scale of measurement that has an inherent zero value defined is the a. ratio scale. b. nominal scale. c. ordinal scale. d. interval scale.

A. ratio scale

A two-tailed test is performed at the .05 level of significance. The p-value is determined to be .09. The null hypothesis a. must be rejected. b. should not be rejected. c. could be rejected, depending on the sample size. d. has been designed incorrectly

A. should not be rejected

The p-value is a probability that measures the support (or lack of support) for a. the null hypothesis. b. the alternative hypothesis. c. either the null or the alternative hypothesis. d. neither the null nor the alternative hypothesis.

A. the null hypothesis

In a questionnaire, respondents are asked to mark their gender as male or female. Gender is an example of a(n) a. categorical variable. b. quantitative variable. c. interval-scale variable. d. ordinal-scale variable.

A. categorical

A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 80 and 12 respectively. The standard error of the mean a. 1.20 b. 0.12 c. 8.00 d. 0.80

A. 1.20

A sample of 200 elements from a population with a known standard deviation is selected. For an interval estimation of μ, the proper distribution to use is the a. normal distribution. b. t distribution with 200 degrees of freedom. c. t distribution with 201 degrees of freedom. d. t distribution with 199 degrees of freedom

A. Normal Distribution

The error of rejecting a true null hypothesis is a. a Type I error. b. a Type II error. c. always negligible in hypothesis testing. d. never committed in hypothesis testing.

A. Type 1 error

What type of error occurs if you retain H0 when, in fact, it is false? a. Type II b. Type I c. either Type I or Type II, depending on the level of significance d. either Type I or Type II, depending on whether the test is one-tailed or two-tailed

A. Type 2

In general, higher confidence levels provide a. wider confidence intervals. b. narrower confidence intervals. c. a smaller standard error. d. unbiased estimates.

A. Wider confidence intervals

In hypothesis testing, the critical value is a. a number that establishes the boundary of the rejection region. b. the probability of a Type I error. c. the probability of a Type II error. d. the same as the p-value.

A. a number that establishes the boundary of rejection region

The sample statistic, such as x bar, s , or , p bar that provides the point estimate of the population parameter is known as a. a point estimator. b. a parameter. c. a population parameter. d. a population statistic.

A. a point estimator

In interval estimation, as the sample size becomes larger, the interval estimate a. becomes narrower. b. becomes wider. c. remains the same, because the mean is not changing. d. gets closer to 1.96.

A. becomes narrower

Given that z is a standard normal random variable, what is the probability that z -2.12? a. 0.4830 b. 0.9830 c. 0.017 d. 0.966

B. .9830

Using an α = .04, a double-sided confidence interval for a population proportion is determined to be .65 to .75. For the same data, if α is decreased, the confidence interval for the population proportion a. becomes narrower. b. becomes wider. c. uses a zero margin of error. d. remains the same.

B. Becomes wider

As the sample size increases, the variability among the sample means a. increases. b. decreases. c. remains the same. d. depends upon the specific population being sampled.

B. Decreases

As a general guideline, the research hypothesis should be stated as the a. null hypothesis. b. alternative hypothesis. c. tentative hypothesis. d. hypothesis the researcher wants to disprove.

B. alternative hypothesis

1. When the level of confidence decreases, the margin of error a. stays the same. b. becomes smaller. c. becomes larger. d. becomes smaller or larger, depending on the sample mean.

B. becomes smaller

As the number of degrees of freedom for a t distribution increases, the difference between the t distribution and the standard normal distribution a. becomes larger. b. becomes smaller. c. stays the same. d. fluctuates.

B. becomes smaller

The standard deviation of a standard normal distribution a. is always equal to 0 b. is always equal to 1 c. can be any positive value. d. can be any value.

B. is always equal to 1

Parameters are a. numerical characteristics of a sample. b. numerical characteristics of a population. c. the averages taken from a sample. d. numerical characteristics of either a sample or a population

B. numerical characteristics of a population

The scale of measurement that is used to rank order the observation for a variable is called the a. ratio scale b. ordinal scale c. nominal scale d. interval scale.

B. ordinal scale

The purpose of statistical inference is to provide information about the a. sample based upon information contained in the population. b. population based upon information contained in the sample. c. population based upon information contained in the population. d. mean of the sample based upon the mean of the population.

B. population based upon information contained in the sample

A normal distribution with a mean of 0 and a standard deviation of 1 is called a. a probability density function. b. uniform probability distribution. c. a standard normal distribution. d. exponential probability distribution.

C. a standard normal distribution

Arithmetic operations provide meaningful results for variables that a. use any scale of measurement except nominal. b. appear as non-numerical values. c. are quantitative. d. have non-negative values.

C. are quantitative

In developing an interval estimate, if the population standard deviation is unknown a. it is impossible to develop the interval estimate. b. the standard deviation is arrived at using the range. c. the sample standard deviation must be used. d. it is assumed that the population standard deviation is 1.

C. the sample standard deviation must be used

z is a standard normal random variable. The P (-1.20 <= z <= 1.50) equals a. 0.0483 b. 0.3849 c. 0.4332 d. 0.8181

D. .8181

The p-value a. can be any negative value. b. can be any positive value. c. must be a number between -1 and 0. d. must be a number between zero and 1

D. Must be a number between 0 and 1

Social security numbers consist of numeric values. Therefore, social security number is an example of a. a quantitative variable. b. either a quantitative or a categorical variable. c. an exchange variable. d. a categorical variable.

D. categorical

The power curve provides the probability of a. correctly accepting the null hypothesis. b. incorrectly accepting the null hypothesis. c. incorrectly rejecting the null hypothesis. d. correctly rejecting the null hypothesis.

D. correctly rejecting the null hypothesis

If the null hypothesis is rejected at the 5% level of significance, it a. will always be rejected at the 1% level. b. will always not be rejected at the 1% level. c. will never be tested at the 1% level. d. may be rejected or not rejected at the 1% level.

D. may be rejected or not rejected at the 1% level

In hypothesis testing, if the null hypothesis has been rejected when the alternative hypothesis is true, a. a Type I error has been committed. b. a Type II error has been committed. c. either a Type I or a Type II error has been committed. d. the correct decision has been made.

D. the correct decision has been made

The probability of committing a Type I error when the null hypothesis is true as an equality is a. the confidence level. b. β. c. greater than 1. d. the level of significance.

D. the level of significance

If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error a. will also increase from .01 to .05. b. will not change. c. will decrease. d. will increase.

c. will decrease