You wish to estimate, with 99% confidence, the population proportion of U.S. adults who support labeling legislation for genetically modified organisms (GMOs). Your estimate must be accurate within 2% of the population proportion. a. No preliminary estimate is available. Find the minimum sample size needed. b. Find the minimum sample size needed, using a prior survey that found that 75% of U.S. adults support labeling legislation for GMOs. c. Compare the results from parts (a) and (b).
> You are analyzing the sample of car batteries in Exercise 21. The population standard deviation of the batteries’ reserve capacities should be less than 0.25 hour. Does the confidence interval you constructed for s suggest that the variation in the batte
> You are analyzing the sample of cough syrup bottles in Exercise 14. The population standard deviation of the volumes of the bottles’ contents should be less than 0.025 fluid ounce. Does the confidence interval you constructed for s suggest that the varia
> The random variable x is normally distributed with the given parameters. Find each probability. a. µ = 9.2, σ ≈ 1.62, P(x < 5.97) b. µ = 87, σ ≈ 19, P(x > 40.5) c. µ = 5.5, σ ≈ 0.08, P(5.36 < x < 5.64) d. µ = 18.5, σ ≈ 4.25, P(19.6 < x < 26.1)
> You are analyzing the sample of bolts in Exercise 13. The population standard deviation of the bolts’ diameters should be less than 0.5 inch. Does the confidence interval you constructed for s suggest that the variation in the bolts’ diameters is at an a
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The prices of a random sample of 20 new m
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The waiting times (in minutes) of a rando
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The record high daily temperatures (in de
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The reserve capacities (in hours) of 18 r
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. As part of a survey, you ask a random sam
> What happens to the shape of the chi-square distribution as the degrees of freedom increase?
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. As part of a water quality survey, you te
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The numbers of touchdowns scored by 11 ra
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The durations (in days) of 14 randomly se
> Find each probability using the standard normal distribution. a. P(z > -1.68) b. P(z < 2.23) c. P(-0.47 < z < 0.47) d. P(z < -1.992 or z > -0.665)
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The final exam scores of 24 randomly sele
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The annual earnings
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The volumes (in flu
> Assume the sample is from a normally distributed population and construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Interpret the results. The diameters (in i
> Construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Assume the sample is from a normally distributed population. c = 0.98, σ = 278.1, n = 41
> Construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Assume the sample is from a normally distributed population. c = 0.90, σ = 35, n = 18
> Construct the indicated confidence intervals for a. the population variance σ2 and b. the population standard deviation σ. Assume the sample is from a normally distributed population. c = 0.99, σ2 = 0.64, n = 7
> Does a population have to be normally distributed in order to use the chi-square distribution?
> Use the confidence interval to find the margin of error and the sample proportion. (0.512, 0.596)
> Use the confidence interval to find the margin of error and the sample proportion. (0.245, 0.475)
> In a survey of U.S. adults, 16% say they have had someone take over their email accounts without their permission. You randomly select 250 U.S. adults and ask them whether they have had someone take over their email accounts without their permission. Fin
> Use the confidence interval to find the margin of error and the sample proportion. (0.905, 0.933)
> Let p be the population proportion for the situation. Find point estimates of p and q. In a survey of 2016 U.S. adults, 665 believe America should stop terrorism at all costs.
> Let p be the population proportion for the situation. Find point estimates of p and q. In a survey of 2016 U.S. adults, 1310 think mainstream media is more interested in making money than in telling the truth.
> Let p be the population proportion for the situation. Find point estimates of p and q. In a survey of 1040 U.S. adults, 478 believe the government should be able to access encrypted communications when investigating crimes.
> The equation for determining the sample size can be obtained by solving the equation for the margin of error for n. Show that this is true and justify each step. n = pgl E E =
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 1052 parents of children ages 8–14, 68% say they are willing to get a second or part-time job to pay for their children’s college education, and 42% s
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 3539 U.S. adults, 47% believe the economy is getting better. Three weeks prior to this survey, 53% believed the economy was getting better. The survey
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 1035 U.S. adults, 37% say the U.S. spends too little on defense. The survey’s margin of error is ±4%.
> In a survey of U.S. adults, 16% say they have had someone take over their email accounts without their permission. You randomly select 250 U.S. adults and ask them whether they have had someone take over their email accounts without their permission. Det
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 1000 U.S. adults, 71% think teaching is one of the most important jobs in our country today. The survey’s margin of error is ±3%.
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 1503 U.S. adults, 79% say people have the right to nonviolent protest. The survey’s margin of error is ±2.9%.
> Let p be the population proportion for the situation. Find point estimates of p and q. In a survey of 1040 U.S. adults, 62 have had someone impersonate them to try to claim tax refunds.
> Translate the statement into a confidence interval. Approximate the level of confidence. In a survey of 1003 U.S. adults, 70% said being able to speak English is at the core of national identity. The survey’s margin of error is ±3.4%
> Use the figure, which shows the results of a survey in which 2000 U.S. college graduates from the year 2016 were asked questions about employment. In Exercise 27, does it seem possible that any of the population proportions could be equal? Explain.
> Use the figure, which shows the results of a survey in which 2000 U.S. college graduates from the year 2016 were asked questions about employment. Construct a. a 95% confidence interval and b. a 99% confidence interval for the population proportion of
> Use the figure, which shows the results of a survey in which 1003 adults from the United States, 1020Â adults from Canada, 999 adults from France, 1000 adults from Japan, and 1000 adults from Australia were asked whether national identity is s
> Use the figure, which shows the results of a survey in which 1003 adults from the United States, 1020Â adults from Canada, 999 adults from France, 1000 adults from Japan, and 1000 adults from Australia were asked whether national identity is s
> In Exercise 20(b), would a sample size of 600 be acceptable? Explain. From Exercise 20(b): Find the minimum sample size needed, using a prior study that found that 31% of motor vehicle fatalities were caused by alcohol-impaired driving.
> In Exercise 17(b), would a sample size of 200 be acceptable? Explain. From Exercise 17(b): Find the minimum sample size needed, using a prior survey that found that 25% of U.S. adults think Congress is doing a good or excellent job.
> In a standardized IQ test, scores are normally distributed, with a mean score of 100 and a standardized deviation of 15. Are you more likely to randomly select one person with an IQ score greater than 105 or are you more likely to randomly select a sampl
> In Exercise 14, does it seem possible that the population proportion could be within 1% of the point estimate? Explain. From Exercise 14: Construct a 99% confidence interval for the population proportion. Interpret the results. In a survey of 600 United
> In Exercise 11, does it seem possible that the population proportion could equal 0.59? Explain. From Exercise 11: Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence in
> You wish to estimate, with 95% confidence, the population proportion of motor vehicle fatalities that were caused by alcohol-impaired driving. Your estimate must be accurate within 5% of the population proportion. a. No preliminary estimate is available
> You wish to estimate, with 90% confidence, the population proportion of U.S. adults who eat fast food four to six times per week. Your estimate must be accurate within 3% of the population proportion. a. No preliminary estimate is available. Find the mi
> You wish to estimate, with 95% confidence, the population proportion of U.S. adults who think Congress is doing a good or excellent job. Your estimate must be accurate within 4% of the population proportion. a. No preliminary estimate is available. Find
> In a survey of 1000 U.S. adults, 490 oppose allowing transgender students to use the bathrooms of the opposite biological sex. Construct a 90% confidence interval for the population proportion of U.S. adults who oppose allowing transgender students to us
> In a survey of 1,626,773 U.S. adults, 49,311 personally identify as lesbian, gay, bisexual, or transgender. Construct a 95% confidence interval for the population proportion of U.S. adults who personally identify as lesbian, gay, bisexual, or transgender
> Construct a 99% confidence interval for the population proportion. Interpret the results. In a survey of 600 United Kingdom teachers, 226 say they would wear a body camera in school.
> In a standardized IQ test, scores are normally distributed, with a mean score of 100 and a standardized deviation of 15. A random sample of 60 people is selected from this population. What is the probability that the mean IQ score of the sample is greate
> Construct a 99% confidence interval for the population proportion. Interpret the results. In a survey of 1000 U.S. adults, 700 think police officers should be required to wear body cameras while on duty.
> Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. In a survey of 2241 U.S. adults in a recent year, 650 made a New Year’s resolution to eat healthier.
> Construct 90% and 95% confidence intervals for the population proportion. Interpret the results and compare the widths of the confidence intervals. In a survey of 2241 U.S. adults in a recent year, 1322 say they have made a New Year’s resolution.
> Use the confidence interval to find the margin of error and the sample proportion. (0.087, 0.263)
> Determine whether the statement is true or false. If it is false, rewrite it as a true statement. To estimate the value of p, the population proportion of successes, use the point estimate x.
> Construct the indicated confidence interval for the population mean m using the t-distribution. Assume the population is normally distributed. c = 0.90, x = 12.5, σ = 2.0, n = 6
> Find the margin of error for the values of c, s, and n. c = 0.98, s = 4.7, n = 9
> Find the margin of error for the values of c, s, and n. c = 0.90, s = 2.4, n = 35
> Find the margin of error for the values of c, s, and n. c = 0.99, s = 3, n = 6
> Find the margin of error for the values of c, s, and n. c = 0.95, s = 5, n = 16
> In a standardized IQ test, scores are normally distributed, with a mean score of 100 and a standardized deviation of 15. What is the highest score that would still place a person in the bottom 10% of the scores?
> A company manufactures light bulbs. The company wants the bulbs to have a mean life span of 1000 hours. This average is maintained by periodically testing random samples of 16 light bulbs. If the t-value falls between -t0.99 and t0.99, then the company w
> A company manufactures tennis balls. When its tennis balls are dropped onto a concrete surface from a height of 100 inches, the company wants the mean height the balls bounce upward to be 55.5 inches. This average is maintained by periodically testing ra
> In Exercise 38, does it seem possible that the population mean could be within 10% of the sample mean? Explain.
> Find the critical value tc for the level of confidence c and sample size n. c = 0.98, n = 40
> In Exercise 36, does it seem possible that the population mean could equal half the sample mean? Explain. From Exercise 36: In a random sample of 18 months from June 2008 through September 2016, the mean interest rate for 30-year fixed rate conventional
> Use the standard normal distribution or the t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a recent season, the population
> Use the standard normal distribution or the t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. The gas mileages (in miles per gall
> Use the standard normal distribution or the t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 18 months fro
> Use the standard normal distribution or the t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 50 people, th
> In Exercise 32, the population mean salary is $61,000. Does the t-value fall between -t0.98 and t0.98?
> In a standardized IQ test, scores are normally distributed, with a mean score of 100 and a standardized deviation of 15. What is the lowest score that would still place a person in the top 5% of the scores?
> The five-year success rate of kidney transplant surgery from living donors is 86%. The surgery is performed on six patients. a. Construct a binomial distribution. b. Graph the binomial distribution using a histogram and describe its shape. c. Find the
> In Exercise 31, the population mean salary is $72,000. Does the t-value fall between -t0.98 and t0.98?
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 98% confidence interval for the population mean. The annual earnings (in dollars) of 40 randomly selected intermediate level life insurance underwri
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 98% confidence interval for the population mean. The annual earnings (in dollars) of 32 randomly selected magnetic resonance imaging technologists
> In Exercise 28, the population mean weekly time spent on homework by students is 7.8 hours. Does the t-value fall between -t0.99 and t0.99?
> Find the critical value tc for the level of confidence c and sample size n. c = 0.99, n = 16
> In Exercise 25, the population mean SAT score is 1020. Does the t-value fall between -t0.99 and t0.99?
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 99% confidence interval for the population mean. Assume the population is normally distributed. The weekly time spent (in hours) on homework for 18
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 99% confidence interval for the population mean. Assume the population is normally distributed. The weekly time (in hours) spent weight lifting for
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 99% confidence interval for the population mean. Assume the population is normally distributed. The grade point averages of 14 randomly selected co
> Use the data set to a. find the sample mean, b. find the sample standard deviation, and c. construct a 99% confidence interval for the population mean. Assume the population is normally distributed. The SAT scores of 12 randomly selected high school
> Find the indicated probabilities using the geometric distribution, the Poisson distribution, or the binomial distribution. Then determine whether the events are unusual. If convenient, use a table or technology to find the probabilities. About 60% of U.S
> You research repair costs of mobile devices and find that the population mean is $89.56. In Exercise 20, does the t-value fall between -t0.95 and t0.95?
> You research prices of cell phones and find that the population mean is $431.61. In Exercise 19, does the t-value fall between -t0.95 and t0.95?
> You research driving distances to work and find that the population standard deviation is 5.2 miles. Repeat Exercise 18 using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results.
> You research commute times to work and find that the population standard deviation is 9.3 minutes. Repeat Exercise 17 using the standard normal distribution with the appropriate calculations for a standard deviation that is known. Compare the results. F
> You are given the sample mean and the sample standard deviation. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 95% confidence interval for the population mean. Interpret the results.
> Find the critical value tc for the level of confidence c and sample size n. c = 0.95, n = 12
> You are given the sample mean and the sample standard deviation. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 95% confidence interval for the population mean. Interpret the results.
> You are given the sample mean and the sample standard deviation. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 95% confidence interval for the population mean. Interpret the results.
> You are given the sample mean and the sample standard deviation. Assume the population is normally distributed and use the t-distribution to find the margin of error and construct a 95% confidence interval for the population mean. Interpret the results.
> Use the confidence interval to find the margin of error and the sample mean. (16.2, 29.8)
> Find the indicated probabilities using the geometric distribution, the Poisson distribution, or the binomial distribution. Then determine whether the events are unusual. If convenient, use a table or technology to find the probabilities. One out of every
> Use the confidence interval to find the margin of error and the sample mean. (64.6, 83.6)
