Questions from Applied Statistics

Q: A random sample of 100 items is drawn from a population whose

A random sample of 100 items is drawn from a population whose standard deviation is known to be σ = 50. The sample mean is x bar = 850. a. Construct an interval estimate for μ with 95 percent confiden...

Q: The fuel economy of a 2011 Lexus RX 350 2WD 6 cylinder

The fuel economy of a 2011 Lexus RX 350 2WD 6 cylinder 3.5 L automatic 5-speed using premium fuel is normally distributed with a known standard deviation of 1.25 MPG. If a random sample of 10 tanks of...

Q: Guest ages at a Vail Resorts ski mountain typically have a right

Guest ages at a Vail Resorts ski mountain typically have a right-skewed distribution. Assume the standard deviation (σ) of age is 14.5 years. (a) Even though the population distribution of age is righ...

Q: On average, 28 patients per hour arrive in the Foxboro 24

On average, 28 patients per hour arrive in the Foxboro 24-Hour Walk-in Clinic on Friday between 6 p.m. and midnight. (a) What is the approximate probability of more than 35 arrivals? (b) What is the a...

Q: The Ball Corporation’s beverage can manufacturing plant in Fort Atkinson, Wisconsin

The Ball Corporation’s beverage can manufacturing plant in Fort Atkinson, Wisconsin, uses a metal supplier that provides metal with a known thickness standard deviation σ = .000959 mm. If a random sam...

Q: Find a confidence interval for μ assuming that each sample is from

Find a confidence interval for μ assuming that each sample is from a normal population. a. x bar = 24, s = 3, n = 7, 90 percent confidence b. x bar = 42, s = 6, n = 18, 99 percent confidence c. x bar...

Q: For each value of d.f. (degrees of freedom

For each value of d.f. (degrees of freedom), look up the value of Student’s t in Appendix D for the stated level of confidence. Then use Excel to find the value of Student’s t to four decimal places....

Q: Find the interval within which 95 percent of the sample

Find the interval within which 95 percent of the sample means would be expected to fall, assuming that each sample is from a normal population. a. μ = 200, σ = 12, n = 36 b. μ = 1,000, σ = 15, n =...

Q: A sample of 21 minivan electrical warranty repairs for “loose,

A sample of 21 minivan electrical warranty repairs for “loose, not attached” wires (one of several electrical failure categories the dealership mechanic can select) showed a mean repair cost of $45.66...

Q: A random sample of monthly rent paid by 12 college seniors living

A random sample of monthly rent paid by 12 college seniors living off campus gave the results below (in dollars). Find a 99 percent confidence interval for μ, assuming that the sample is...