Child development theorists freud to erikson to spock

Statistics Exam 2

Question 1 (3.33 points) Question 1 Unsaved

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p.

n = 87, x = 48; 98 percent

Question 1 options:

0.447 < p < 0.657

0.428 < p < 0.676

0.448 < p < 0.656

0.427 < p < 0.677

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Question 2 (3.33 points) Question 2 Unsaved

Use the given degree of confidence and sample data to construct a confidence interval for the population mean μ. Assume that the population has a normal distribution.

n = 12, sample mean (x-bar) = 26.8, s = 6.8, 99 percent

Question 2 options:

20.70 < μ < 32.90

20.72 < μ < 32.88

21.46 < μ < 32.14

20.58 < μ < 33.02

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Question 3 (3.33 points) Question 3 Unsaved

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p.

n = 144, x = 82; 90 percent

Question 3 options:

0.501 < p < 0.637

0.505 < p < 0.633

0.503 < p < 0.635

0.500 < p < 0.638

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Question 4 (3.33 points) Question 4 Unsaved

Solve the problem.

The following confidence interval is obtained for a population proportion, p:

(0.293, 0.317)

Use these confidence interval limits to find the margin of error, E.

Question 4 options:

0.010

0.013

0.024

0.012

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Question 5 (3.33 points) Question 5 Unsaved

Solve the problem.

Find the value of -zα/2 that corresponds to a level of confidence of 96.68 percent.

Question 5 options:

0.0166

-1.84

2.13

-2.13

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Question 6 (3.33 points) Question 6 Unsaved

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p.

Of 89 adults selected randomly from one town, 67 have health insurance. Find a 90% confidence interval for the true proportion of all adults in the town who have health insurance.

Question 6 options:

0.663 < p < 0.842

0.635 < p < 0.871

0.678 < p < 0.828

0.646 < p < 0.859

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Question 7 (3.33 points) Question 7 Unsaved

Use the confidence level and sample data to find a confidence interval for estimating the population μ.

A random sample of 100 full-grown lobsters had a mean weight of 22 ounces and a standard deviation of 3.7 ounces. Construct a 98 percent confidence interval for the population mean μ.

Question 7 options:

20 < μ < 22

21 < μ < 23

21 < μ < 24

22 < μ < 24

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Question 8 (3.33 points) Question 8 Unsaved

Solve the problem.

The following confidence interval is obtained for a population proportion, p:

(0.870, 0.894)

Use these confidence interval limits to find the point estimate, (p-bar) .

Question 8 options:

0.882

0.885

0.870

0.894

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Question 9 (3.33 points) Question 9 Unsaved

Use the confidence level and sample data to find the margin of error E.

The duration of telephone calls directed by a local telephone company: population standard deviation = 3.0 minutes, n = 580, 97 percent confidence.

Question 9 options:

0.057 minutes

0.011 minutes

0.270 minutes

0.006 minutes

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Question 10 (3.33 points) Question 10 Unsaved

Express the null hypothesis H0 and the alternative hypothesis H1 in symbolic form. Use the correct symbol (μ, p, σ )for the indicated parameter.

A researcher claims that 62% of voters favor gun control.

Question 10 options:

H0: p < 0.62

H1: p ≥ 0.62

H0: p ≥ 0.62

H1: p < 0.62

H0: p = 0.62

H1: p ≠ 0.62

H0: p ≠ 0.62

H1: p = 0.62

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Question 11 (3.33 points) Question 11 Unsaved

Find the P-value for the indicated hypothesis test.

In a sample of 47 adults selected randomly from one town, it is found that 9 of them have been exposed to a particular strain of the flu. Find the P-value for a test of the claim that the proportion of all adults in the town that have been exposed to this strain of the flu is 8%.

Question 11 options:

0.0048

0.0262

0.0024

0.0524

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Question 12 (3.33 points) Question 12 Unsaved

Express the null hypothesis H0 and the alternative hypothesis H1 in symbolic form. Use the correct symbol (μ, p, σ )for the indicated parameter.

An entomologist writes an article in a scientific journal which claims that fewer than 12 in ten thousand male fireflies are unable to produce light due to a genetic mutation. Use the parameter p, the true proportion of fireflies unable to produce light.

Question 12 options:

H0: p = 0.0012

H1: p > 0.0012

H0: p > 0.0012

H1: p ≤ 0.0012

H0: p = 0.0012

H1: p < 0.0012

H0: p < 0.0012

H1: p ≥ 0.0012

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Question 13 (3.33 points) Question 13 Unsaved

Formulate the indicated conclusion in nontechnical terms. Be sure to address the original claim.

The owner of a football team claims that the average attendance at games is over 794, and he is therefore justified in moving the team to a city with a larger stadium. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in nontechnical terms.

Question 13 options:

There is sufficient evidence to support the claim that the mean attendance is less than 794.

There is not sufficient evidence to support the claim that the mean attendance is greater than 794.

There is not sufficient evidence to support the claim that the mean attendance is less than 794.

There is sufficient evidence to support the claim that the mean attendance is greater than than 794.

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Question 14 (3.33 points) Question 14 Unsaved

Find the P-value for the indicated hypothesis test.

In a sample of 88 children selected randomly from one town, it is found that 8 of them suffer from asthma. Find the P-value for a test of the claim that the proportion of all children in the town who suffer from asthma is equal to 11%.

Question 14 options:

0.2843

0.2157

-0.2843

0.5686

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Question 15 (3.33 points) Question 15 Unsaved

Express the null hypothesis H0 and the alternative hypothesis H1 in symbolic form. Use the correct symbol (μ, p, σ )for the indicated parameter.

A cereal company claims that the mean weight of the cereal in its packets is at least 14 oz.

Question 15 options:

H0: μ = 14

H1: μ > 14

H0: μ < 14

H1: μ ≥ 14

H0: μ > 14

H1: μ ≤ 14

H0: μ = 14

H1: μ < 14

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Question 16 (3.33 points) Question 16 Unsaved

Use the given information to find the P-value.

The test statistic in a left-tailed test is z = -2.05.

Question 16 options:

0.0453

0.0202

0.5000

0.4798

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Question 17 (3.33 points) Question 17 Unsaved

Formulate the indicated conclusion in nontechnical terms. Be sure to address the original claim.

An entomologist writes an article in a scientific journal which claims that fewer than 18 in ten thousand male fireflies are unable to produce light due to a genetic mutation. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is to reject the null hypothesis, state the conclusion in nontechnical terms.

Question 17 options:

There is not sufficient evidence to support the claim that the true proportion is less than 18 in ten thousand.

There is sufficient evidence to support the claim that the true proportion is greater than 18 in ten thousand.

There is sufficient evidence to support the claim that the true proportion is less than 18 in ten thousand.

There is not sufficient evidence to support the claim that the true proportion is greater than 18 in ten thousand.

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Question 18 (3.33 points) Question 18 Unsaved

Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z value used to test a null hypothesis.

α = 0.1 for a two-tailed test.

Question 18 options:

±1.645

±1.4805

±2.33

±2.052

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Question 19 (3.33 points) Question 19 Unsaved

Determine whether the samples are independent or consist of matched pairs.

The effect of caffeine as an ingredient is tested with a sample of regular soda and another sample with decaffeinated soda.

Question 19 options:

Matched pairs

Independent samples

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Question 20 (3.33 points) Question 20 Unsaved

The two data sets are dependent. Find the average deviation (d-bar) to the nearest tenth.

A: 52 55 60 63 51

B: 29 25 20 25 22

Question 20 options:

41.6

32.0

40.0

19.2

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Question 21 (3.33 points) Question 21 Unsaved

Find sd.

The differences between two sets of dependent data are 0.42 0.26 0.26 0.3 0.28. Round to the nearest hundredth.

Question 21 options:

0.11

0.07

0.21

0.04

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Question 22 (3.33 points) Question 22 Unsaved

Find sd.

The differences between two sets of dependent data are -9 3 -9 6. Round to the nearest tenth.

Question 22 options:

181.7

7.9

4.0

6.3

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Question 23 (3.33 points) Question 23 Unsaved

Find sd.

The differences between two sets of dependent data are -8 -9 -9 -6 -7. Round to the nearest tenth.

Question 23 options:

1.3

2.6

1.7

1.0

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Question 24 (3.33 points) Question 24 Unsaved

Determine the decision criterion for rejecting the null hypothesis in the given hypothesis test; i.e., describe the values of the test statistic that would result in rejection of the null hypothesis.

We wish to compare the means of two populations using paired observations. Suppose that d-bar = 3.125, Sd = 2.911, and n = 8, and that you wish to test the following hypothesis at the 1 percent level of significance:

H0: μd = 0 against H1: μd > 0.

What decision rule would you use?

Question 24 options:

Reject H0 if test statistic is greater than 2.998.

Reject H0 if test statistic is less than 2.998.

Reject H0 if test statistic is greater than -2.998.

Reject H0 if test statistic is greater than -2.998 and less than 2.998.

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Question 25 (3.33 points) Question 25 Unsaved

Assume that you want to test the claim that the paired sample data come from a population for which the mean difference is μd = 0. Compute the value of the t test statistic.

A farmer has decided to use a new additive to grow his crops. He divided his farm into 10 plots and kept records of the corn yield (in bushels) before and after using the additive. The results are shown below.

Plot: 1 2 3 4 5 6 7 8 9 10

Before 9 9 8 7 6 8 5 9 10 11

After 10 9 9 8 7 10 6 10 10 12

You wish to test the following hypothesis at the 10 percent level of significance.

Ho: μD = 0 against H1: μD ≠ 0.

What is the value of the appropriate test statistic?

Question 25 options:

2.536

2.033

5.014

1.584

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Question 26 (3.43 points) Question 26 Unsaved

Find the required χ2-value.

For a χ2-curve with 7 degrees of freedom, find the χ2-value having area 0.05 to its right.

Question 26 options:

15.507

14.067

3.325

2.167

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Question 27 (3.33 points) Question 27 Unsaved

Find the required χ2-value.

For a χ2-curve with 24 degrees of freedom, find .

Question 27 options:

13.848

12.401

36.415

13.091

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Question 28 (3.33 points) Question 28 Unsaved

Find the required χ2-value.

For a χ2-curve with 12 degrees of freedom, find .

Question 28 options:

23.336

19.675

21.026

5.226

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Question 29 (3.33 points) Question 29 Unsaved

Find the value of the chi-square test statistic for the goodness-of-fit test.

You wish to test the claim that workplace accidents are distributed on workdays as follows: In a study of 100 workplace accidents, 27 occurred on a Monday, 13 occurred on a Tuesday, 15 occurred on a Wednesday, 13 occurred on a Thursday, and 32 occurred on a Friday. What is the value of the χ2 test statistic? The observed frequencies and the expected frequencies are shown below.

Question 29 options:

χ2 = 2.286

χ2 = 5.333

χ2 = 0.889

χ2 = 0.827

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Question 30 (3.33 points) Question 30 Unsaved

Group the bivariate data into a contingency table.

The table below provides data on sex, political party affiliation, and income bracket for a sample of people questioned during a poll. Group the bivariate data for the two variables "sex" and "political party" into a contingency table.

M Rep High

F Dem Middle

F Dem Middle

M Dem Low

F Other Middle

M Rep Low

F Rep High

M Rep High

M Dem High

F Rep Low

M Dem High

F Rep Middle

F Dem Middle

M Dem Middle

M Rep Low

F Dem High

M Rep Low

F Other High

M Other Middle

F Dem Low

M Dem Middle

M Rep Low

F Dem Middle

Question 30 options: