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If the margin of error? increases, the confidence interval? _____________.

Select one:

a. gets wider

b. stays the same.

c. gets narrower

Between 2000 and 2005, 30% of Americans applying for passports listed Asia as their destination. Passport officials have the sense that this percentage has increased in the last couple of years. To check this sense, officials take a random sample of 100 recent applications. Of these, 41 listed an Asian country as their destination.

In this context, the parameter of interest, p is:

Select one:

a. the proportion of those in the sample who planned to go to Asia

b. the proportion of Americans applying for passports between 2000 and 2005 who planned to go to Asia

c. the proportion of Americans applying for passports since 2005 who planned to go to Asia

d. The proportion of Americans applying for passports who planned to go to Asia

Fill in the blank.

If the level of confidence? increases, the confidence interval? ______________.

Select one:

a. gets narrower.

b. stays the same.

c. gets wider.

In a criminal jury? trial, one option is to declare the defendant? "not guilty". In a hypothesis test this is equivalent to which? conclusion?

Select one:

a. Reject the null hypothesis.

b. Accept the null hypothesis as true.

c. Fail to reject the null hypothesis.

Fill in the blank.

The probability of seeing sample data like those seen? (or something even less? likely) given the null hypothesis is true is the? _________________.

Select one:

a. p-value

b. alternative hypothesis.

c. z-score

d. null hypothesis

A recent NYTimes/CBS poll asked a random sample of 1060 adults whether they felt that the country was heading in the right direction. Only 328 of the respondents felt that this was the case. Obtain an 80% confidence interval for the percentage of all adults who feel that the country is heading in the right direction.

Hint: To compute the confidence by hand using the formula:

Select one:

a. 29.1% to 32.8%

b. 27.7% to 34.2%

c. 28.1% to 33.8%

d. 0.307 to 0.311

A research company polled a random sample of 604 teens about Internet use. 46?% of those teens reported that they had misrepresented their age online to gain access to websites and online services.

Explain the meaning of p^ =0.46 in the context of this situation.

Hint: Carefully read and understand each multiple choice option before selecting your final answer. There is only one correct answer.

Select one:

a. The meaning of p^ = 0.46 is that 46% of the 604 teens in the sample said they have misrepresented their age online. This is the? researchers' best estimate of p^ with the proportion of the 604 teens in the sample who said they had done so.

b. The meaning of p^ = 0.46 is that the researchers have? 95% confidence that 46% of all U.S. teens would say that they have misrepresented their age online.

c. The meaning of p^ =0.46 is that 46?% of the 604 teens in the sample said they have misrepresented their age online. This is the? researchers' best estimate of? p, the proportion of all U.S. teens who would say they have done so.

d. The meaning of p^ = 0.46 is that the researchers have? 95% confidence that 46% of the 604 teens in the sample said they have misrepresented their age online.

Macular Degeneration is the leading cause of vision loss, affecting more than 10 million Americans - more than cataracts and glaucoma combined. A research article reports the results of a new drug test. The drug is found to decrease vision loss in people with Macular Degeneration.

The article gives a p-value of 0.004 in the analysis section. Which of the following interpretation of this p-value is correct?

Select one:

a. The probability of getting a result as extreme or more extreme that the one in this study if the drug is actually not effective.

b. The probability that the drug is effective

c. The probability that the drug is not effective

d. The probability of getting a result as extreme or more extreme that the one in this study if the drug is actually effective.

We wish to test the null hypothesis H₀: p = 0.80 against the alternative hypothesis H_A: p ≠ 0.80. In a sample of size n = 200, the sample proportion is 0.715. Compute the p-value in this case.

Select one:

a. 0.0013

b. 0.0026

c. 0.9974

d. 0.9987

A newspaper reports that the government’s approval rating stands at 65%. The article adds that the poll is based on a random sample of 985 adults and has a margin of error of 2.5%. What level of confidence did the pollster use?

Hint: Recall the margin of error is given by the formula:

Solve for Z* given that M = 0.025, p^ = 0.65, n = 985

Select one:

a. 80%

b. 90%

c. 95%

d. 99%

A 95% confidence interval for the unknown population proportion p is 0.68 to 0.74. We interpret the confidence interval as follows:

Select one:

a. Ninety-five percent (95%) of all possible values for p lie in the interval 0.68 to 0.74

b. If we repeat the study many times, 95% of the confidence intervals will contain p. We hope that our interval is one of the 95% and not one of the 5% of intervals that do not contain p.

c. Ninety-five percent (95%) of the population lie between 0.68 and 0.74.

d. If we repeat the study many times, on 95% of occasions p will fall in the interval 0.68 to 0.74. We hope that in our study p does fall in this interval.

A statistics teacher asks each of his students to randomly pick and write down one of the numbers 0, 1, 2, 3, or 4. His theory is that the proportion who pick the number 0 will be less than expected from true random selection. Call p the population proportion that would pick the number 0. What are the appropriate hypotheses in this case?

Select one:

a. H0: p = 0.5 HA: p ≠ 0.5

b. H0: p = 0.5 HA: p < 0.5

c. H0: p = 0.2 HA: p ≠ 0.2

d. H0: p = 0.2 HA: p < 0.2

A friend of yours claims to be psychic. You are skeptical. To test this you take a stack of 52 playing cards and have your friend try to identify the suit? (hearts, diamonds,? clubs, or? spades), without? looking, of? course! If you were to do a hypothesis test on this? experiment, would your alternative hypothesis be? one-sided or ?two-sided? Explain why.

Select one:

a. The alternative hypothesis would be? one-sided because the only evidence that would support your? friend's claim is guessing less than? 1/4 of the suits correctly.

b. The alternative hypothesis would be? two-sided because the only evidence that would support your? friend's claim is guessing more or less than? 1/4 of the suits correctly.

c. The alternative hypothesis would be? one-sided because the only evidence that would support your ?friend's claim is guessing more than? 1/4 of the suits correctly.

d. The alternative hypothesis would be? two-sided because the only evidence that would support your ?friend's claim is guessing less than? 1/4 of the suits correctly.

A graduate student is designing a research study. She is hoping to show that the results of an experiment are statistically significant (i.e., to reject the null hypothesis). What type of p-value would she want to obtain?

Select one:

a. A very large p-value

b. A very small p-value

c. The magnitude of the p-value has no impact on statistical significance

d. Either a very large or a very small p-value

Between 2000 and 2005, 30% of Americans applying for passports listed Asia as their destination. Passport officials have the sense that this percentage has increased in the last couple of years. To check this sense, officials take a random sample of 100 recent applications. Of these, 41 listed an Asian country as their destination.

In this case the p-value is:

Select one:

a. 0.0764

b. 0.0618

c. 0.0125

d. 0.0082

Fill in the blank.

In a confidence? interval, the amount we reach out on either side of the sample proportion is called the?______________.

Select one:

a. confidence interval.

b. sampling variability.

c. sample size.

d. margin of error.

Over a two week period a random sample of 200 children were interviewed as they left the zoo. Forty-two of the children reported that the elephants were their favorite animal. Using 90% confidence, the margin of error for estimating the proportion of all young visitors who favor elephants is:

Hint: The margin of error formula is:

Select one: