Exam 9: Statistical Inference: Hypothesis Testing for Single Populations

Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks.One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans.Last Friday's sample contained 30 defaulted loans.Using $\alpha$ = 0.10, the appropriate decision is to _______.

(Multiple Choice)

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Question 21

If the p-value for a one-tailed test is 0.019, then the null hypothesis

(Multiple Choice)

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Question 22

Discrete Components, Inc.manufactures a line of electrical resistors.Presently, the carbon composition line is producing 100-ohm resistors.The population variance of these resistors "must not exceed 4" to conform to industry standards.Periodically, the quality control inspectors check for conformity by randomly select 10 resistors from the line, and calculating the sample variance.The last sample had a variance of 4.36.Assume that the population is normally distributed.Using $\alpha$ = 0.05, the critical value of chi-square is _________________.

(Multiple Choice)

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Question 23

A home building company routinely orders standard interior doors with a height of 80 inches.Recently the installers have complained that the doors are not the standard height.The quality control inspector for the home building company is concerned that the manufacturer is supplying doors that are not 80 inches in height.In an effort to test this, the inspector is going to gather a sample of the recently received doors and measure the height.The alternative hypothesis for the statistical test to determine if the doors are not 80 inches is __________.

(Multiple Choice)

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Question 24

Elwin Osbourne, CIO at GFS, Inc., suspects that at least 25% of e-mail messages sent by GFS employees are not business related.A random sample of 300 e-mail messages was selected to test this hypothesis at the 0.01 level of significance.Fifty-four of the messages were not business related.The appropriate decision is to _______.

(Multiple Choice)

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Question 25

Consider the following null and alternative hypotheses. H_o: $\mu$ = 67 H_a: $\mu$ $\neq$ 67 These hypotheses ______________.

(Multiple Choice)

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Question 26

The rejection and nonrejection regions are divided by a point called the critical value.

(True/False)

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Question 27

If the null hypothesis is in reality false, but the sample data leads the analyst to fail to reject the null, then the analysts has made a Type II error.

(True/False)

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Question 28

When using the t test to test a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is defined as n - 1.

(True/False)

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Question 29

The lifetime of a squirrel follows a normal distribution with mean μ = 40 months and a standard deviation $\sigma$ = 7 months.To test the hypothesis that μ > 40, 25 squirrels are randomly selected.Assuming that μ = 45, and α = 0.1, the power is approximately

(Multiple Choice)

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Question 30

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 in a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

(Multiple Choice)

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Question 31

The weight of a USB flash drive is 30 grams and is normally distributed.Periodically, quality control inspectors at Dallas Flash Drives randomly select a sample of 17 USB flash drives.If the mean weight of the USB flash drives is too heavy or too light the machinery is shut down for adjustment; otherwise, the production process continues.The last sample showed a mean and standard deviation of 31.9 and 1.8 grams, respectively.Using $\alpha$ = 0.10, the appropriate decision is to _______.

(Multiple Choice)

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Question 32

Jennifer Cantu, VP of Customer Services at Tri-State Auto Insurance, Inc., monitors the claims processing time of the claims division.Her standard includes "a mean processing time of 5 days or less." Each week, her staff checks for compliance by analyzing a random sample of 60 claims.Jennifer's null hypothesis is ________.

(Multiple Choice)

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Question 33

If the observed chi-squared value is more than the critical chi-squared value found on the related table, then the null hypothesis is rejected.

(True/False)

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Question 34

The null and the alternative hypotheses must be mutually exclusive and collectively exhaustive.

(True/False)

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Question 35

Discrete Components, Inc.manufactures a line of electrical resistors.Presently, the carbon composition line is producing 100-ohm resistors.The population variance of these resistors "must not exceed 4" to conform to industry standards.Periodically, the quality control inspectors check for conformity by randomly selecting 10 resistors from the line, and calculating the sample variance.The last sample had a variance of 4.36.Assume that the population is normally distributed.Using $\alpha$ = 0.05, the null hypothesis is _________________.

(Multiple Choice)

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Question 36

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

(True/False)

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Question 37

Ophelia O'Brien, VP of Consumer Credit of American First Banks (AFB), monitors the default rate on personal loans at the AFB member banks.One of her standards is "no more than 5% of personal loans should be in default." On each Friday, the default rate is calculated for a sample of 500 personal loans.Last Friday's sample contained 30 defaulted loans.Using $\alpha$ = 0.10, the observed z value is _______.

(Multiple Choice)

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(39)

Question 38

A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief, a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchases were of this company's brand.If a researcher wants to conduct a statistical test for this problem, the alternative hypothesis would be _______.

(Multiple Choice)

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Question 39

In testing a hypothesis about a population variance, the chi-square test is fairly robust to the assumption the population is normally distributed.

(True/False)

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Question 40

Showing 21 - 40 of 123

If the p-value for a one-tailed test is 0.019, then the null hypothesis

Consider the following null and alternative hypotheses. H_o: $\mu$ = 67 H_a: $\mu$ $\neq$ 67 These hypotheses ______________.

The rejection and nonrejection regions are divided by a point called the critical value.

If the null hypothesis is in reality false, but the sample data leads the analyst to fail to reject the null, then the analysts has made a Type II error.

When using the t test to test a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is defined as n - 1.

The lifetime of a squirrel follows a normal distribution with mean μ = 40 months and a standard deviation $\sigma$ = 7 months.To test the hypothesis that μ > 40, 25 squirrels are randomly selected.Assuming that μ = 45, and α = 0.1, the power is approximately

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 in a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

If the observed chi-squared value is more than the critical chi-squared value found on the related table, then the null hypothesis is rejected.

The null and the alternative hypotheses must be mutually exclusive and collectively exhaustive.

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

In testing a hypothesis about a population variance, the chi-square test is fairly robust to the assumption the population is normally distributed.

Introduction to Statistics and Business Analytics

Visualizing Data With Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Exam 9: Statistical Inference: Hypothesis Testing for Single Populations

If the p-value for a one-tailed test is 0.019, then the null hypothesis

Consider the following null and alternative hypotheses. Ho: μ\muμ = 67 Ha: μ\muμ ≠\neq= 67 These hypotheses ______________.

The rejection and nonrejection regions are divided by a point called the critical value.

If the null hypothesis is in reality false, but the sample data leads the analyst to fail to reject the null, then the analysts has made a Type II error.

When using the t test to test a hypothesis about a population mean with an unknown population standard deviation ( σ\sigmaσ )the degrees of freedom is defined as n - 1.

The lifetime of a squirrel follows a normal distribution with mean μ = 40 months and a standard deviation σ\sigmaσ = 7 months.To test the hypothesis that μ > 40, 25 squirrels are randomly selected.Assuming that μ = 45, and α = 0.1, the power is approximately

A researcher is testing a hypothesis of a single mean.The critical z value for α\alphaα = .05 in a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.

If the observed chi-squared value is more than the critical chi-squared value found on the related table, then the null hypothesis is rejected.

The null and the alternative hypotheses must be mutually exclusive and collectively exhaustive.

When a researcher fails to reject a false null hypothesis, a Type II error has been committed.

In testing a hypothesis about a population variance, the chi-square test is fairly robust to the assumption the population is normally distributed.

Introduction to Statistics and Business Analytics

Visualizing Data With Charts and Graphs

Descriptive Statistics

Probability

Discrete Distributions

Continuous Distributions

Sampling and Sampling Distributions

Statistical Inference: Estimation for Single Populations

Statistical Inferences About Two Populations

Analysis of Variance and Design of Experiments

Simple Regression Analysis and Correlation

Multiple Regression Analysis

Building Multiple Regression Models

Time-Series Forecasting and Index Numbers

Analysis of Categorical Data

Nonparametric Statistics

Statistical Quality Control

Decision Analysis

Filters

Consider the following null and alternative hypotheses. H_o: $\mu$ = 67 H_a: $\mu$ $\neq$ 67 These hypotheses ______________.

When using the t test to test a hypothesis about a population mean with an unknown population standard deviation ( $\sigma$ )the degrees of freedom is defined as n - 1.

The lifetime of a squirrel follows a normal distribution with mean μ = 40 months and a standard deviation $\sigma$ = 7 months.To test the hypothesis that μ > 40, 25 squirrels are randomly selected.Assuming that μ = 45, and α = 0.1, the power is approximately

A researcher is testing a hypothesis of a single mean.The critical z value for $\alpha$ = .05 in a two-tailed test is +1.96.The observed z value from sample data is 2.85.The decision made by the researcher based on this information is to _____ the null hypothesis.