(a) If X is the sample mean Young's modulus for a random sample of n = 16 sheets, where is the sampling distribution of X centered, and what is the standard deviation of the X distribution? E(X) = GPa GPa (b) Answer the questions posed in part (a) for a sample size of n = 64 sheets. E(X) = GPa GPa

X is a normally distributed random variable with a mean of 5 and a standard deviation of 2. For which value of a is P(X > a) = 0.6293? What is a?

(a) Find the mean u and the standard deviation o for the collection of N = 8 stocks. (b) Find the sample mean i and sample standard deviation s of the random sample of stocks.

Suppos are interested in studying a population to estimate its mean. The population is normal and has a standard deviation of G=23. We have taken a random sample of size 11=95 from the population. This is Sample 1 in the table below. (In the table, Sample 1 is written "S1", Sample 2 is written "S2", etc.) As shown in the table, the sample mean of Sample 1 is = 142.0. Also shown are the lower and upper limits of the 80% confidence interval for the population mean using this sample, as well as the lower and upper limits of the 95% confidence interval. Suppose that the true mean of the population is = 140, which is shown on the displays for the confidence intervals. Press the "Generate Samples" button to simulate taking 19 more random samples of size 11 = 95 from this same population. (The 80% and 95% confidence intervals for all of the samples are shown in the table and graphed.) Then complete parts (a) through (c) below the table. 80% 80% 95% 95% lower upper lower upper limit limit…

K A population has a mean μ = 134 and a standard deviation o = 26. Find the mean and standard deviation of the sampling distribution of sample means with sample size n = 59. σ- The mean is μ- =, and the standard deviation is o- = (Round to three decimal places as needed.) X Z-

A person's blood glucose level and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution that is approximately normal with mean μ = 88 and standard deviation σ = 21. Note: After 50 years of age, both the mean and standard deviation tend to increase. For an adult (under 50) after a 12-hour fast, find the following probabilities. (Round your answers to four decimal places.) (a) x is more than 60(b) x is less than 110(c) x is between 60 and 110(d) x is greater than 140 (borderline diabetes starts at 140)