Exam 11: Two-Sample Tests of Hypothesis

If we are testing for the difference between two population proportions, it is assumed that the two samples are large enough that the binomial distribution can be approximated by ______.

(Short Answer)

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Question 21

The paired t test is especially appropriate when the two samples are ________.

(Short Answer)

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Question 22

A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? What is the p-value for this hypothesis test?

(Multiple Choice)

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Question 23

If two dependent samples of size 20 are used to test the difference between the means, the degrees of freedom for a t-statistic are 19.

(True/False)

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Question 24

When the standard deviations are equal but unknown, a test for the differences between two population means has n - 1 degrees of freedom.

(True/False)

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Question 25

A study by a bank compared the average savings of customers who were depositors for three years or less with those who had been depositors for more than three years. The results of a sample are: To test that the two groups of customers have equal savings rates, what is the critical value of z using α = 0.05?

(Short Answer)

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Question 26

The pooled estimate of the proportion is found by dividing the total number of successes by ___________________________.

(Short Answer)

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Question 27

An investigation of the effectiveness of a training program to improve customer relationships included a pre-training and post-training customer survey. To compare the differences, they computed (post-training survey score - pre-training survey score). Seven customers were randomly selected and completed both surveys. The results follow. This analysis is an example of _____________.

(Multiple Choice)

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Question 28

Which condition must be met to conduct a test for the difference in two sample means using a z-statistic?

(Multiple Choice)

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Question 29

If we are testing for the difference between two population proportions, it is assumed that the two populations follow the ________________ distribution.

(Short Answer)

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Question 30

To compare the effect of weather on sales of soft drinks, a distributor surveyed people in two regions of the country and asked if they purchased soft drinks in the last month. The following are the results. The distributor would like to know if there is a difference in sales between the two regions. Using the 1% level of significance, what is the critical value?

(Short Answer)

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Question 31

Two samples, one of size 14 and the second of size 13, are selected to test the difference between two population means. How many degrees of freedom are used to find the critical value? Assume the population standard deviations are equal.

(Multiple Choice)

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Question 32

When testing the null hypothesis that two population means are equal, the hypothesized difference between the population means is ________________.

(Short Answer)

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Question 33

If the null hypothesis that two means are equal is true, where will 97% of the computed z values lie between?

(Multiple Choice)

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Question 34

If two dependent samples of size 100 are used to test the difference between the means, the degrees of freedom for a t-statistic are _____.

(Short Answer)

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Question 35

A sample of 250 adults tried the new multigrain cereal "Wow!" A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. What is the pooled proportion?

(Multiple Choice)

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Question 36

A financial planner wants to compare the yield of income and growth mutual funds. Fifty thousand dollars is invested in each of a sample of 35 income and 40 growth funds. The mean increase for a two-year period for the income funds is $900. For the growth funds, the mean increase is $875. Income funds have a sample standard deviation of $35; growth funds have a sample standard deviation of $45. Assume that the population standard deviations are equal. At the 0.05 significance level, is there a difference in the mean yields of the two funds? What is the null hypothesis?

(Essay)

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Question 37

A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? Based on the p-value, what is your conclusion?

(Multiple Choice)

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Question 38

When testing for a difference between the means of two dependent samples, the sample test statistic is a ______________.

(Short Answer)

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Question 39

If a hypothesis states that one population mean is greater than another population mean, then the test is _______________.

(Short Answer)

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Question 40

Showing 21 - 40 of 122

If we are testing for the difference between two population proportions, it is assumed that the two samples are large enough that the binomial distribution can be approximated by ______.

The paired t test is especially appropriate when the two samples are ________.

If two dependent samples of size 20 are used to test the difference between the means, the degrees of freedom for a t-statistic are 19.

When the standard deviations are equal but unknown, a test for the differences between two population means has n - 1 degrees of freedom.

The pooled estimate of the proportion is found by dividing the total number of successes by ___________________________.

Which condition must be met to conduct a test for the difference in two sample means using a z-statistic?

If we are testing for the difference between two population proportions, it is assumed that the two populations follow the ________________ distribution.

Two samples, one of size 14 and the second of size 13, are selected to test the difference between two population means. How many degrees of freedom are used to find the critical value? Assume the population standard deviations are equal.

When testing the null hypothesis that two population means are equal, the hypothesized difference between the population means is ________________.

If the null hypothesis that two means are equal is true, where will 97% of the computed z values lie between?

If two dependent samples of size 100 are used to test the difference between the means, the degrees of freedom for a t-statistic are _____.

A sample of 250 adults tried the new multigrain cereal "Wow!" A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. What is the pooled proportion?

When testing for a difference between the means of two dependent samples, the sample test statistic is a ______________.

If a hypothesis states that one population mean is greater than another population mean, then the test is _______________.

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Methods and the Central Limit Theorem

Estimation and Confidence Intervals

One-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Nonparametric Methods: Goodness-Of-Fit Tests

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