We have provided summary statistics for independent simple random samples from two populations. In each case, use the pooled t-test and the pooled t-interval procedure to conduct the required hypothesis test and obtain the specified confidence interval. x1 = 20, s1 = 4, n1 = 10, x2 = 23, s2 = 5, n2= 15 a. Left-tailed test, α = 0.05 b. 95% confidence interval

A 90% confidence interval for a population mean is (10, 20). What is the margin of error of the interval?

if n = 42, p = 0.6 then construct the 98% confidence interval for the population proportion.

The following results come from two independent random samples taken of two populations. Sample 1 Sample 2 n1 = 60 n2 = 25 X1 = 13.6 X2 = 11.6 01 = 2.4 02 = 3 (a) What is the point estimate of the difference between the two population means? (Use x, - x,.) (b) Provide a 90% confidence interval for the difference between the two population means. (Use x, - x,. Round your answers to two decimal places.) to (c) Provide a 95% confidence interval for the difference between the two population means. (Use x, - x,. Round your answers to two decimal places.) to