Homework answers / question archive / Q1 The Nissan Leaf (Leading, Environmentally friendly, Affordable, Family car) is a five-door hatchback electric car manufactured by Nissan and introduced in 2010

Q1 The Nissan Leaf (Leading, Environmentally friendly, Affordable, Family car) is a five-door hatchback electric car manufactured by Nissan and introduced in 2010

Statistics

Share With

Q1 The Nissan Leaf (Leading, Environmentally friendly, Affordable, Family car) is a five-door hatchback electric car manufactured by Nissan and introduced in 2010. The combined fuel economy of the Nissan is 99 miles per gallon (mpg) gasoline equivalent. Assume the mpg for the Nissan Leaf is normally distributed with mean 99 and standard deviation 8, N(99, 8). For quality control, Nissan randomly samples cars produced each day to test their mpg. Each random sample contains 15 cars. a. For the random sample of 15 cars, what is the expected value of the sample average: E (X)? b. For the random sample of 15 cars, what is the standard error of the mean? c. What is the chance the sample mean is greater than 100 mpg? d. What is the chance the sample mean is less than 95 mpg?

Q2 Confidence intervals for proportions a. A manufacturer conducted a survey among 400 randomly selected target market households in the test market for its new disposable diapers. The objective of the survey was to determine the market share for its new brand. If the sample point estimate for market share is 18%, develop a 95% confidence interval. b. Can the company reasonably conclude that they have a 22% market share?