The ages of a group of 127 randomly selected adult females have a standard deviation of 17.5 years. Assume that the ages of female statistics students have less variation than ages of females in the general population, so let o = 17.5 years for the sample size calculation. How many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? Assume that we want 99% confidence that the sample mean is within one-half year of the population mean. Does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population? The required sample size is. (Round up to the nearest whole number as needed.)

The age of student at a university are normally distributed with a mean of 20. What percentage of the student body is at least 20 years old?

QUESTION 3 What percent of scores are below an SAT score of 560?

A company wants to assess the average time it takes for customers to complete a particular task on their website. They collect the following data from a sample of 10 customers: 5, 6, 7, 8, 9, 10, 10, 11, 12, 13 minutes. Calculate the sample mean and standard deviation for this data.

What is the equation for The standard deviation of the distribution of sample means

QUESTION 7 Given an x-mean3D3.4, SSx-97.3, y-mean33.9, SSy-45.2, Sxy-55.5, and a sample size of 45, calculate the following: X Sample Standard Deviation and Y Sample Standard Deviation X Population Standard Deviation and Y Population Standard Deviation Sample Covariance and Population Covariance Sample Correlation and Population Correlation

The distribution of the student heights at a large college is approximately bell shaped. If the mean height is 66 inches,and approximately 95% of the heights fall between 32 and 100 inches, then, the standard deviation of the heightdistribution is approximately equal to

Butt-to-knee length is approximately normally distributed with a mean of 23.1 inches and a standard deviation of 1.2.  Theater seats are designed to be comfortable for as many adults as possible.  If the seats are required to fit the middle 80% of the population, the seat must be comfortable for what butt-to-knee length range?

QUESTION 2 What percent of scores are above an ACT score of 19?