A tire manufacturer would like to estimate the average tire life of its new all-season light truck tire in terms of how many miles it lasts. Determine the sample size needed to construct a 97% confidence interval with a margin of error equal to 2.300 milles. Assume the standard deviation for the tire life of this particular brand is 9,000 miles. The sample size needed is

Q: A laboratory tested 58 chicken eggs and found that the mean amount of cholesterol was 109…

A: Given Information: Sample size (n) = 58 Sample mean (x¯) = 109 milligrams Population standard…

Q: A professor is trying to find the average exam grade in his class. The sample mean should be within…

A: It is given that confidence level is 0.90, standard deviation is 12 and margin of error E is 5.

Q: An Army official wants to estimate the mean weight of a particular type of weapon.  He takes a…

A: Given that, Mean = 48.1 Standard deviation = 0.12 Sample size = 100 98% confidence level

Q: According to the National Health Statistics Report, a sample of 360 one year old baby boys in the US…

A:

Q: the standard deviation of the 16 observations was 0.95 inches (again, the sample mean was 17.2).…

A: Given :  Standard deviation of the 16 observations was 0.95 inches & the sample mean was 17.2.…

Q: SAT scores are normally distributed with a mean of 1,500 and a standard deviation of 300. An…

A:

Q: In a random sample of 15 ​people, the mean driving distance to work was 18.5 miles and the standard…

A:

Q: random sample of eight ​people, the mean driving distance to work was 23.6 miles and the standard…

A: Given, sample mean (x̄) = 23.6 sample standard deviation (s) = 5.1 sample size (n) = 8

Q: Find the critical t value to use in making a 90% confidence interval for a mean if the sample size…

A: Given, confidence level = 90.0 Need to find Critical value t

Q: Determine the 99.5 percent confidence interval that contains the population variance if the sample…

A:

Q: A runner wants to know her average mile running time. She records a sample of 25 running times. The…

A: Solution: Let X be the mile running time. From the given information, x-bar=6.5 minutes, s=0.7…

Q: Amanda Reaves , a zookeeper, wants to estimate the average weight gain of elephants who are on a new…

A: Solution: From the given information, confidence level is 0.90, σ=5.50 and E=0.95.

Q: A researcher wants to estimate the number of hours that senior high school students spend on social…

A: Sample size, n = 50. Mean spending time, x¯ =5. Population Standard deviation, σ=0.5. Confidence…

Q: A food snack manufacturer samples 11 bags of pretzels off the assembly line and weighs their…

A:

Q: SAT scores are normally distributed with a mean of 1,500 and a standard deviation of 300. An…

A:

Q: You would like to estimate the variance and standard deviation for credit scores based on FICO.…

A: Construct the 95% confidence interval estimate for the variance of credit scores Obtain the critical…

Q: Sales personnel for City Distributors Inc. submit weekly reports listing the customer complaints…

A: Given Information: Sample size (n) = 8 Sample mean (x¯) = 8 Sample standard deviation (s) = 3.464 To…

Q: In a random sample of twelve ​people, the mean driving distance to work was 18.8 miles and the…

A: From the given information we want to construct 90% confidence interval.

Q: Find the Margin of Error, if we are asked for 90% confidence interval where the mean is 52.3, the…

A: The provided information are: Confidence level = 90% Population standard deviation (σ)=2.15 Sample…

Q: You measure 33 backpacks' weights, and find they have a mean weight of 50 ounces. Assume the sample…

A: The sample mean = 50 ounces. Sample standard deviation, s is 6.5 ounces. The sample size, n is 33.