Question: A paper manufacturer requires a minimum strength of 20 pounds per square inch. To check on the quality of the paper, a random sample of 10 pieces of paper is selected each hour from the previous hour’s production and a strength measurement is recorded for each. Assume that the strength measurements are normally distributed with a standard deviation ? = 2 pounds per square inch. Required: What is the approximate sampling distribution of the sample mean of ? = 10 test pieces of paper? If the mean of the population of strength measurements is 21 pounds per square inch, what is the approximate probability that, for a random sample of ? = 10 test pieces of paper, ?̅ = 20?

A population has a mean μ=138 and a standard deviation σ=23. Find the mean and standard deviation of the sampling distribution of sample means with sample size n=41.

There are 120 students at Francis Howell North High School. Mr. Willott conducts a poll that asks 20 randomly selected students how many hours of sleep they got last night. They find that the mean amount of sleep is 6.7 hours. The population standard deviation is o = 2 hours. Can we estimate the standard deviation of the sampling distribution of means by using %3D V20 0.447 hours? O No, because we don't know that the distribution of sleep hours for the population is approximately Nor. O No, because we can't be sure that the central limit theorem applies to this situation. O Yes, because all the conditions for using this formula have been met. O No, because "hours of sleep" is not a continuous variable. O No, because the sample is more than 10% of the population.

Suppose a random sample of 4949 measurements is selected from a population with mean 6060 and standard deviation 1010.         Step 2 of 2:  Find the standard deviation of the sampling distribution of sample means using the given information. Round to two decimal place, if necessary.