Executives of a supermarket chain are interested in the amount of time that customers spend in the stores during shopping trips. The executives hire a statistical consultant and ask her to determine the mean shopping time, μ, of customers at the supermarkets. The consultant will collect a random sample of shopping times at the supermarkets and use the mean of these shopping times to estimate μ. Assuming that the standard deviation of the population of shopping times at the supermarkets is 26 minutes, what is the minimum sample size she must collect in order for her to be 90%confident that her estimate is within 5 minutes of μ? Carry your intermediate computations to at least three decimal places. Write your answer as a whole number (and make sure that it is the minimum whole number that satisfies the requirements).

The average sale price (online) for 4-year-old Harley Davidson touring motorcycles is approximately normally distributed with a mean of $14,000 and a standard deviation of $4000. Find the 30th percentile for the prices of this type of motorcycle.

Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a 0.05 significance level to test for a difference between the measurements from the two arms. What can be concluded? Right arm Left arm 150 142 120 131 167 160 179 156 In this example, Hd is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the measurement from the right arm minus the measurement from the left arm. What are the null and alternative hypotheses for the hypothesis test? O A. Ho: Hd = 0 H₁: Hd 0 Since the P-value is than the significance level, the null hypothesis. There sufficient evidence to support the claim of a difference in measurements between the two arms.

A distributor's average daily customer demand is 400 units. The standard deviation of customer demand is 30 units. If the distributor would like to maintain a 98% service level (Z score = 2.05) and the supplier's lead time is 9 days, how much safety stock should be held? O 123 units O 185 units O 36,000 units O 554 units

The weight loss for the first six months of a diet program is normally distributed with an average 40 pounds and a standard deviation of 20 pounds. How much weight would a participant have to loss to be in the 90th percentile?

A nutritionist wants to determine how much time nationally people spend eating and drinking. Suppose for a random sample of 911 people age 15 or​ older, the mean amount of time spent eating or drinking per day is 1.68 hours with a standard deviation of 0.59 hour. Complete parts ​(a) through ​(d) below. ​(a) A histogram of time spent eating and drinking each day is skewed right. Use this result to explain why a large sample size is needed to construct a confidence interval for the mean time spent eating and drinking each day.     A. Since the distribution of time spent eating and drinking each day is normally​ distributed, the sample must be large so that the distribution of the sample mean will be approximately normal.   B. The distribution of the sample mean will never be approximately normal.   C. The distribution of the sample mean will always be approximately normal. Your answer is not correct.   D. Since the distribution of time spent eating and drinking…

Find the mean, standard deviation, and relative standard deviation for the set of measurements (7, 18, 10, 15).