Star and Tribune newspaper, there is an article entitled “1 in 8 school buses fail tests.”   The article says that the overall statewide proportion of school buses that fail safety tests is 9%.  However, one bus company has a higher rate of over 12%.  Assume that we want a new estimate for the statewide proportion of school buses that fail the safety inspection.    How large a sample would you have to take in order to construct a 95% confidence interval estimate for the true proportion of buses that fail the inspection and achieve a margin of error of plus or minus 5%?

Q: According to a poll, 81% of California adults (409 out of 506 surveyed) feel that education is one…

A: Point estimate=0.81

Q: In a 2017 survey was conducted on what was the best day of the week.  The result indicated that 90%…

A: Margin of error is given by, And Confidence interval for this study,

Q: Suppose you want to produce an estimate on the percent of students who return to college after their…

A:

Q: Suppose we wanted to estimate the average amount of sleep (in hours) a college student gets a night.…

A: Confidence interval : Confidence interval is a range of values it contains the true population…

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A: It is given that Sample size n = 250 Number of students receiving scholarship, X = 70 The critical…

Q: 88% of California adults (444 out of 506 surveyed) feel that education is one of the top issues…

A: The value of z at a 90% confidence level is 1.645, which can be obtained by using the standard…

Q: Suppose that the a college wants to have an idea of the average SAT score of the incoming freshman…

A: The confidence level is 0.90, the standard deviation is 310 and margin of error E is 50.

Q: As Senior Class President, one of your lifelong duties is overseeing the planning of your high…

A:

Q: An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential…

A: The random variable flu follows binomial distribution. X ~ B (n, p). The sample size is 337. The…

Q: You plan to construct a 90% confidence interval for the proportion of all middle school students who…

A:

Q: It is known that ticks in York County carry the Lyme disease.  In a representative sample of 200…

A: Let n=sample size, X=number of Carry disease. p^=x/n  X=167, n=200

Q: According to a report on consumer fraud and identity theft, Indiana had 1671 complaints of identity…

A:

Q: According to a past poll conducted of Lexington residents, 52% indicated support for a light rail…

A: Given, p^=0.52 n=400 α=1-0.95=0.05 As per z-distribution table, the critical value of z is obtained…

Q: You plan to conduct a survey to find out the proportion of students who enjoy taking classes…

A: Given  The margin of error is given as m=0.02 At a 90% confidence interval, α=0.1 As the proportion…

Q: The Bureau of Alcohol, Tobacco, and Firearms (BATF) has been concerned about lead levels in…

A: Given, Range = 49 to 720 Margin of Error E = 10 at 90% confidence level  α = 0.1Critical value Zα2 =…

Q: Refer to the following scenario. An epidemiologist is worried about the prevalence of the flu in…

A: The formula of sample size is, Use EXCEL Procedure for finding the critical value of z.   Follow…

Q: If subject 101is 71 years old. Divide the age by 10 and put a % on it, that is your desire margin of…

A: Solution:The formula for the sample size is as follows:

Q: ccording to a past poll conducted of Lexington residents, 52% indicated support for a light rail…

A: Given: Sample proportion p^=52%=0.52 Sample size (n) = 400

Q: Suppose that a health expert has claimed that 28% of college students smoke cigarettes. To…

A: Given 95% confidence interval for the percentage of college students who smoke is 19% to 24%. Given…

Q: It is believed that slightly over 50% of Americans own pets. A 95% confidence interval for the…

A: Confidence Interval: The form of the confidence interval is, CI = Point estimate ± Margin of error…

Q: A sample of 1,000 employees in an international company was taken to estimate the average…

A: Confidence interval of mean is given by, (X bar + - Z* sigma/√n) Where X bar is mean and sigma is…

Q: A high school counselor is interested in determining factors that contribute to high school drop out…

A: Solution; Given information: n1=41 Sample size of high school  graduatesn2= 38 Sample size of high…

Q: An insurance company collects data on seat-belt use among drivers in a country. 90% confidence…

A: Givenn1=2000p1^=28%=0.28P2^=xn2=4821500=0.32α=1-0.90=0.10α2=0.05zc=zα2=z0.05=1.6449      (from z…

Q: Your professor wishes to estimate the proportion of ALL high school students enrolled in…

A:

Q: wenty years ago, a very famous psychologist specializing in marriage counseling authored a book…

A: Solution: Given information n= 275 Sample size of couples who bought book. X= 217  stayed together…

Q: If 64% of a sample of 550 people leaving a shopping mall claims to have spent over $25 create and…

A: Given,   Sample size = 550 Sample proportion = 0.64   Critical value: Using z-table, the z-critical…

Q: A statistics instructor was interested in the proportion of all Kent State students who live on…

A: The proportion that students at Kent State live on campus is obtained below:From the given…

Q: Refer to the following scenario. An epidemiologist is worried about the prevalence of the flu in…

A: To find the sample size required for estimating the population proportion with a 95% confidence…

Q: According to a past study, it was believed that 1.4% of the students in the School district did not…

A:

Q: An epidemiologist is worried about the prevalence of the flu in East Vancouver and the potential…

A:

Q: We plan to sample parents in order to construct a 99% confidence interval for the proportion who…

A:

Q: A study was being done to estimate the proportion of students who receive financial aid. If the…

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Q: Ve want to know how many people plan on buying a cell phone this year. Determine the sample size…

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Q: In 2017, the CDC administered the Youth Risk Behavior Survey (YRBS) to a random sample of 14,795…

A: Obtain the 99% confidence interval for the proportion of the high school students have been cyber…

Q: According to a telephone survey of adults, 86% of homeowners said that owning a home was a good…

A: From the given information, According to a telephone survey of adults, 86% of homeowners said that…

Q: In a poll, 1200 adults in a region were asked about their online vs. in-store clothes shopping. One…

A: Note: According to Bartleby expert guidelines, we can answer only first question with their three…

Q: In a survey of 3116 adults aged 57 through 85​ years, it was found that 86.2​% of them used at least…

A: