A car insurance company wants to know what proportion of drivers always wear a seatbelt. They survey a simple random sample of 400 drivers, of which 328 say that they always wear their seatbelt. (a) Compute a 99% confidence interval for the population proportion of drivers who would say that they always wear a seatbelt. Show all your steps and write out the formulas that you use.  (b)  Based on this interval estimate, can we conclude (with 99% confidence) that more than 75% of drivers would say that they always wear a seatbelt? Explain.

Q: There is an ever increasing number of sources of getting the daily news – traditional newspapers,…

A: Given info: A 98% confidence interval to estimate the true proportion of adults who would read…

Q: Lindsey selected a random sample of 25 tomatoes at the farmer's market. The 95% confidence interval…

A: When Lindsey selected a random sample of 25 tomatoes at the farmer's market, she was aiming to…

Q: A sample of 200 found that 43.2% of those sampled consumed more than 2 alcoholic  beverages  a week.…

A: Given:

Q: Suppose that X, Y, and Z are jointly distributed random variables, that is, they are defined on the…

A: Since, you have you have posted a question with multiple subparts we will solve first three subparts…

Q: sample of 97 psychology graduates found an average salary of $71 K/year. Assume ?=$14 K/year. Find…

A: Given Z score 90% confidence interval=1.645 Sigma=14 n=97

Q: Cameron and Bailey each take random samples and construct 90% confidence intervals for the…

A:

Q: A researcher was interested in knowing how many people in the city supported a new tax. She sampled…

A:

Q: A poll of 827 students at Alpha state college found that 61% of those polled preferred a quarter…

A: It is given that the proportion of the students who preferred a quarter system to a trimester…

Q: The Graduate Schools take a random sample of recent MS graduates (n=135) and finds that 12 of these…

A: Givenn=135x=12confidence interval = 90%p^=xn=12135=0.0889α=1-0.90=0.10α2=0.05zc=zα2=z0.05=1.6449…

Q: A researcher wanted to check whether the percentage of Canadian adults with obesity has decreased in…

A: Number of Canadian adults in 2005= 75 Number of Canadian adults in 2009 = 120   significance level =…

Q: A researcher is interested in a 95% confidence interval. It is found to have a point estimate of 2.5…

A: From the provided information, Confidence level = 95% Point estimate = 2.5 Margin of error (E) = 0.6

Q: Suppose you wanted to take another sample of dogs to find a 90% confidence interval of young dogs to…

A:

Q: In a survey of 50,00 people, 80% indicated that they listened to their favorite radio station…

A: Hern= 5000 P^ = 0.80 We have to construct 95% ci for p

Q: We wish to estimate what percent of adult residents in a certain county are parents. Out of 500…

A:

Q: 67% out of 150 pupils from school A passed an exam; 62% of 120 pupils at school B passed. Estimate…

A: Given : n1 = 150 n2 = 120 confidence level,c=0.9

Q: In a random sample of 500 Americans, 25% indicated that they have a cat for a pet. Estimate with 97%…

A:

Q: lorry is a researcher who is curious about the proportion of students who are planning to pursue a…

A:

Q: In a random sample of 500 Americans, 50% indicated that they have a cat for a pet. Estimate with 95%…

A: Given information

Q: business conducts a random sample of 89 of its customers and find that 44 of them think the company…

A:

Q: A random sample of high school students is used to estimate the mean time all high school students…

A: Solution: From the given information, a 99% confidence interval is 1.7 hours to 3.1 hours.

Q: What proportion of college students earn their undergraduate degrees in four years? A college…

A: The formula of the margin of error when the limits given are,

Q: In another pre-election poll, a pollster finds that 442 out of 650 people polled favor Smith.…

A: Given: Total no of people polled , n=650 No. of people favor Smith, x=442 Confidence level=95%

Q: A survey of 300 women shoppers found that 17% of them shop on impulse. What is the 80% confidence…

A: From the provided information,A survey of 300 women shoppers found that 17% of them shop on impulse.…

Q: A scientist claims that 65% of U.S. adults believe humans contribute to an increase in global…

A: Given  A scientist claims that 65% of U.S. adults believe humans contribute to an increase in global…

Q: Suppose researchers are about to draw a sample of 1500 observations from a normally distributed…

A: Sample size, n = 1500 tα/2 = 0.46 We have to find the confidence level.

Q: In a sample of 85 statistics students, 41 said that finding confidence intervals for population…

A: It is given that x is 41 and sample size (n) is 85. The confidence level is 0.99.

Q: In a random sample of 145 students, we find that 53% have attended a baseball game at some point in…

A: Given,sample size (n)=145sample proportion(p^)=0.53α=1-0.95=0.05α2 =0.025z0.025 =1.96

Q: In a hypothetical study (n=300), 100 patients were on antihypertensive medications. Generate a 95%…

A: The objective of this question is to calculate the 95% confidence interval for the true proportion…

Q: A researcher wanted to compare the percentages of men and women who play the lottery.  They randomly…

A:

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: In a random sample of 600 adults, 270 described themselves as vegetarians. Construct a 99%…

A: In a random sample of 600 adults, 270 described themselves as vegetarians.

Q: From a lake, an unknown proportion of fish have been tagged.  You collect a sample of 100 fish taken…

A:

Q: You are working as an assistant to the dean of institutional research at your university. The dean…

A:

Q: Out of 600 people sampled, 240 have shopped online. Based on this, construct a 90% confidence…

A: Find z-critical value:…

Q: A student found that in a random sample of 300 people in a town, 105 play sports. Based on this…

A: Given that, X = 105 N = 300 90% confidence level

Q: Sally is analyzing wheat production. She sampled 700 wheat farmers from across the state. She found…

A:

Q: Of 102 randomly selected adults, 42 were found to have high blood pressure. A 90% confidence…

A:

Q: In a study on drug use in the prison population carried out in 2006, it was found that 63% of…

A: The hypothesized proportion is p0=0.63. The sample size is n=4985. The favorable cases are X=3227.…

Q: A random sample of high school students

A: Here it is given that, A 99% confidence interval based on this sample is 1.7 hours to 3.1 hours

Q: Find the margin of error for the​ 99% confidence interval used to estimate the population…

A: The random variable X follows normal distribution. The sample size is 1100. The proportion value is…

Q: You want to construct a 99% confidence interval for the proportion of retail stores that went out of…

A: The CI for the population proportion, p^±Zp^ (1-p^)nwhere, p^=sample proportion…

Estimation

A new framework of data analysis where the new statistical methods are used for interpreting the results and analyzing the data is known as estimation in statistics.