Find the critical values and xR for the given confidence level c and sample size n.

In an engineering class, students want to determine the difference in the mean strength between two different types of building materials—Type A, which is relatively inexpensive, and Type B, which is slightly more expensive. The students take a random sample of 60 of the Type A building material and a random sample of 27 of the Type B building material. Given the mean strength for each sample, the students construct a 95% confidence interval for the difference in population means.   (a) Determine the degrees of freedom for the conservative approach for finding the t critical value.   (b) Find the t critical value associated with 95% confidence. (Use a table or SALT. Round your answer to two decimal places.)

What are the confidence intervals for: Mean= 5.9 Sd= 3 N=200 α= .01

Find the critical values y, and y for the given confidence level c and sample size n. R c = 0.9, n= 28 (Round to three decimal places as needed.)

Estimate the minimum sample size needed to achieve the margin of error E= 0.026 for a​ 95% confidence interval.

Estimate the minimum sample size needed to achieve the margin of error E = 0.029 for a 95% confidence interval. The minimum sample size is an example (Round up to the nearest integer.)

Estimate the minimum sample size needed to achieve the margin of error E=0.013 for a​ 95% confidence interval.

Estimate the minimum sample size needed to achieve the margin of error E = 0.026 for a 95% confidence interval. The minimum sample size is (Round up to the nearest integer.)

Find the critical values x and xR for the given confidence level c and sample size n. c=0.98, n 23 x = (Round to three decimal places as needed.)