ch.8 interval mean

Question

question 4

Assume that a sample is used to estimate a population mean . Find the 95% confidence interval for a sample of size 68 with a mean of 19.3 and a standard deviation of 10.7.

Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places.

95% C.I. = (X,X)Incorrect

Answer 1

When you are looking for the CI for means, you have to find the critical value for the degrees of freedom of n-1= 68-1=67. You can get this value by using invT on your calculator, or look it up on a chart.