The random variable x is normally distributed with mean µ = 174 and standard deviation σ = 20. Find the indicated probability. P(160 < x < 170)
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.94
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.85
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.05
> In a large section of a history class, the points for the final exam are normally distributed, with a mean of 72 and a standard deviation of 9. Grades are assigned according to the rule below. • The top 10% receive an A. â€
> A vending machine dispenses coffee into an eight-ounce cup. The amounts of coffee dispensed into the cup are normally distributed, with a standard deviation of 0.03 ounce. You can allow the cup to overflow 1% of the time. What amount should you set as th
> You sell a brand of automobile tire that has a life expectancy that is normally distributed, with a mean life of 30,000 miles and a standard deviation of 2500 miles. You want to give a guarantee for free replacement of tires that do not wear well. You ar
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.7995
> The weights of bags of baby carrots are normally distributed, with a mean of 32 ounces and a standard deviation of 0.36 ounce. Bags in the upper 4.5% are too heavy and must be repackaged. What is the most a bag of baby carrots can weigh and not need to b
> 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. Thirty-six perce
> Answer the questions about the specified normal distribution. The pregnancy length (in days) for a population of new mothers can be approximated by a normal distribution, with a mean of 267 days and a standard deviation of 10 days. a. What is the minimu
> Answer the questions about the specified normal distribution. The red blood cell counts (in millions of cells per microliter) for a population of adult males can be approximated by a normal distribution, with a mean of 5.4 million cells per microliter an
> Answer the questions about the specified normal distribution. The test scores for the analytical writing section of the Graduate Record Examination (GRE) can be approximated by a normal distribution, as shown in the figure. a. What is the maximum score
> Answer the questions about the specified normal distribution. The undergraduate grade point averages (UGPA) of students taking the Law School Admission Test in a recent year can be approximated by a normal distribution, as shown in the figure. a. What i
> Answer the questions about the specified normal distribution. A water footprint is a measure of the appropriation of fresh water. The per capita water footprint (in mega gallons) in the U.S. for a recent year can be approximated by a normal distribution,
> Answer the questions about the specified normal distribution. The per capita energy consumption level (in kilowatt-hours) in Venezuela for a recent year can be approximated by a normal distribution, as shown in the figure. a. What consumption level repr
> Answer the questions about the specified normal distribution. In a recent study on world happiness, participants were asked to evaluate their current lives on a scale from 0 to 10, where 0 represents the worst possible life and 10 represents the best pos
> Answer the questions about the specified normal distribution. In a survey of women in the United States (ages 20 –29), the mean height was 64.2 inches with a standard deviation of 2.9 inches. a. What height represents the 95th percentile? b. What heigh
> Find the indicated z-score. Find the positive z-score for which 12% of the distribution’s area lies between -z and z.
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.6736
> 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. During a 77-year
> Find the indicated z-score. Find the positive z-score for which 80% of the distribution’s area lies between -z and z.
> Find the indicated z-score. Find the z-score that has 84.1345% of the distribution’s area to its right.
> Find the indicated z-score. Find the z-score that has 2.275% of the distribution’s area to its left.
> Find the indicated z-score. Find the z-score that has 20.9% of the distribution’s area to its right.
> Find the indicated z-score. Find the z-score that has 63.7% of the distribution’s area to its right.
> Find the indicated z-score. Find the z-score that has 78.5% of the distribution’s area to its left.
> Find the indicated z-score. Find the z-score that has 11.9% of the distribution’s area to its left.
> Find the indicated z-score(s) shown in the graph. Area = Area = 0.05 0.05 z= ? z=?
> Find the indicated z-score(s) shown in the graph. Area = 0.475 Area = 0.475 Z= ?
> Find the indicated z-score(s) shown in the graph. Area = 0.7190
> 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. Eighty-two perce
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.4364
> Find the indicated z-score(s) shown in the graph. Area = 0.0233 z=?
> Find the indicated z-score(s) shown in the graph. Area = 0.5987
> Find the indicated z-score(s) shown in the graph. Area = 0.3520 2- z- 0
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P75
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P91
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P40
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P25
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P67
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P88
> Find the mean, variance, and standard deviation of the binomial distribution for the given random variable. Interpret the results. Fifty-six percent of college student-athletes receive athletics scholarships. You randomly select five college student-athl
> The table lists the number of wireless devices per household in a small town in the United States. a. Construct a probability distribution. b. Graph the probability distribution using a histogram and describe its shape. c. Find the mean, variance, and
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. P30
> Use the Standard Normal Table or technology to find the z-score that corresponds to the cumulative area or percentile. 0.2090
> Find the indicated probabilities. If convenient, use technology to find the probabilities. In a recent year, the MCAT total scores were normally distributed, with a mean of 500 and a standard deviation of 10.6. Find the probability that a randomly select
> Find the indicated probabilities. If convenient, use technology to find the probabilities. In a survey of U.S. women, the heights in the 20- to 29-year age group were normally distributed, with a mean of 64.2 inches and a standard deviation of 2.9 inches
> Find the indicated probabilities. If convenient, use technology to find the probabilities. In a recent study on world happiness, participants were asked to evaluate their current lives on a scale from 0 to 10, where 0 represents the worst possible life a
> The random variable x is normally distributed with mean µ = 174 and standard deviation σ = 20. Find the indicated probability. P(172 < x < 192)
> From a pool of 16 candidates, 9 men and 7 women, the offices of president, vice president, secretary, and treasurer will be filled. a. In how many different ways can the offices be filled? b. What is the probability that all four of the offices are fil
> Use the probability distribution in Exercise 3 to find the probability of randomly selecting a game in which Garrett Temple had a. fewer than four personal fouls, b. at least three personal fouls, and c. between two and four personal fouls, inclusive.
> Find the a. mean, b. variance, c. standard deviation, and d. expected value of the probability distribution. Interpret the results. The table shows the distribution of personal fouls per game for Garrett Temple in a recent NBA season. 1 2 3 4 5
> Find the mean, variance, and standard deviation of the binomial distribution for the given random variable. Interpret the results. About 13% of U.S. drivers are uninsured. You randomly select eight U.S. drivers and ask them whether they are uninsured. Th
> Find the a. mean, b. variance, c. standard deviation, and d. expected value of the probability distribution. Interpret the results. The table shows the distribution of household sizes in the United States for a recent year. 1 2. 3 4 5 6 7 P(x) 0
> A survey of adults in the United States found that 61% ate at a restaurant at least once in the past week. You randomly select 30 adults and ask them whether they ate at a restaurant at least once in the past week. a. Verify that a normal distribution c
> Seventy percent of U.S. adults anticipate major cyberattacks on public infrastructure in the next five years. You randomly select 10 U.S. adults. a. Construct a binomial distribution for the random variable x, the number of U.S. adults who anticipate ma
> A florist has 12 different flowers from which floral arrangements can be made. A centerpiece is made using four different flowers. a. How many different centerpieces can be made? b. What is the probability that the four flowers in the centerpiece are r
> The life spans of car batteries are normally distributed, with a mean of 44 months and a standard deviation of 5 months. a. Find the probability that the life span of a randomly selected battery is less than 36 months. b. Find the probability that the
> The initial pressures for bicycle tires when first filled are normally distributed, with a mean of 70 pounds per square inch (psi) and a standard deviation of 1.2 psi. a. Random samples of size 40 are drawn from this population, and the mean of each sam
> The table shows the results of a survey in which 3,405,100 public and 489,900 private school teachers were asked about their full-time teaching experience. a. Find the probability that a randomly selected private school teacher has 10 to 20 years of ful
> An auto parts seller finds that 1 in every 200 parts sold is defective. Use the geometric distribution to find the probability that a. the first defective part is the fifth part sold, b. the first defective part is the first, second, or third part sold
> Twenty-eight percent of U.S. adults think that climate scientists understand the causes of climate change very well. You randomly select 25 U.S. adults. Find the probability that the number of U.S. adults who think that climate scientists understand the
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. To the left of z = 0.12 or to the right of z = 1.72
> a. construct a binomial distribution, b. graph the binomial distribution using a histogram and describe its shape, and c. identify any values of the random variable x that you would consider unusual. Explain your reasoning. Eighty-eight percent of U.S.
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. Between z = -1.22 and z = -0.26
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. Between z = 0 and z = 2.95
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. To the right of z = -0.84
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. To the left of z = -3.08
> Find the indicated area under the standard normal curve. If convenient, use technology to find the area. To the left of z = 0.72
> The data set represents the weights (in pounds) of 10 randomly selected black bears from northeast Pennsylvania. Assume the weights are normally distributed. a. Find the sample mean and the sample standard deviation. b. Construct a 95% confidence inte
> In a survey of 2096 U.S. adults, 1740 think football teams of all levels should require players who suffer a head injury to take a set amount of time off from playing to recover. a. Find the point estimate for the population proportion. b. Construct a
> Use the standard normal distribution or the t-distribution to construct the indicated confidence interval for the population mean of each data set. Justify your decision. If neither distribution can be used, explain why. Interpret the results. a. In a r
> The data set represents the scores of 12 randomly selected students on the SAT Physics Subject Test. Assume the population test scores are normally distributed and the population standard deviation is 104. a. Find the point estimate of the population me
> Use the confidence interval to find the margin of error and the sample mean. (20.75, 24.10)
> a. construct a binomial distribution, b. graph the binomial distribution using a histogram and describe its shape, and c. identify any values of the random variable x that you would consider unusual. Explain your reasoning. Seventy-six percent of stay-
> a. Construct a 95% confidence interval for the population mean in Exercise 2. Interpret the results. b. Does it seem possible that the population mean could be greater than 12.5 miles? Explain.
> a. Construct a 90% confidence interval for the population mean in Exercise 1. Interpret the results. b. Does it seem possible that the population mean could be within 10% of the sample mean? Explain.
> The driving distances (in miles) to work of 30 people are shown in the table at the left. Assume the population standard deviation is 8 miles. Find a. the point estimate of the population mean µ and b. the margin of error for a 95% confidence interval.
> The waking times (in minutes past 5:00 a.m.) of 40 people who start work at 8:00 a.m. are shown in the table at the left. Assume the population standard deviation is 45 minutes. Find a. the point estimate of the population mean µ and b. the margin of e
> 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 acceleration tim
> 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 maximum wind spe
> Find the critical values x2R and x2L for the level of confidence c and sample size n. c = 0.99, n = 10
> Find the critical values x2R and x2L for the level of confidence c and sample size n. c = 0.90, n = 16
> Find the critical values x2R and x2L for the level of confidence c and sample size n. c = 0.98, n = 25
> Find the critical values x2R and x2L for the level of confidence c and sample size n. c = 0.95, n = 13
> Find the indicated binomial probabilities. If convenient, use technology or Table 2 in Appendix B. Sixty-two percent of U.S. adults get news on social media sites. You randomly select five U.S. adults. Find the probability that the number of U.S. adults
> In Exercise 25(b), would a sample size of 369 be acceptable? Explain.
> You wish to estimate, with 95% confidence, the population proportion of U.S. adults who have taken or planned to take a winter vacation in a recent year. Your estimate must be accurate within 5% of the population proportion. a. No preliminary estimate i
> In Exercise 22, does it seem possible that the population proportion could be within 1% of the point estimate? Explain.
> In Exercise 19, does it seem possible that the population proportion could equal 0.75? Explain. From Exercise 19: In a survey of 1035 U.S. adults, 745 say they want the U.S. to play a leading or major role in global affairs.
> Let p be the population proportion for the situation. a. Find point estimates of p and q, b. construct 90% and 95% confidence intervals for p, and c. interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of
> Let p be the population proportion for the situation. a. Find point estimates of p and q, b. construct 90% and 95% confidence intervals for p, and c. interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of
> Let p be the population proportion for the situation. a. Find point estimates of p and q, b. construct 90% and 95% confidence intervals for p, and c. interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of
> Let p be the population proportion for the situation. a. Find point estimates of p and q, b. construct 90% and 95% confidence intervals for p, and c. interpret the results of part (b) and compare the widths of the confidence intervals. In a survey of
> You research the heights of top-rated roller coasters and find that the population mean is 160 feet. In Exercise 17, does the t-value fall between -t0.95 and t0.95?
> In a random sample of 36 top-rated roller coasters, the average height is 165 feet and the standard deviation is 67 feet. Construct a 90% confidence interval form. Interpret the results.
> Find the indicated binomial probabilities. If convenient, use technology or Table 2 in Appendix B. Eighty-eight percent of U.S. civilian full-time employees have access to medical care benefits. You randomly select nine civilian full-time employees. Find
> a. find the margin of error for the values of c, s, and n, and b. construct the confidence interval for µ using the t-distribution. Assume the population is normally distributed. c = 0.99, s = 16.5, n = 20, x = 25.2
> a. find the margin of error for the values of c, s, and n, and b. construct the confidence interval for µ using the t-distribution. Assume the population is normally distributed. c = 0.98, s = 0.9, n = 12, x = 6.8
> a. find the margin of error for the values of c, s, and n, and b. construct the confidence interval for µ using the t-distribution. Assume the population is normally distributed. c = 0.95, s = 1.1, n = 25, x = 3.5
