Carver Memorial Hospital's surgeons have a new procedure that they think will decrease the time to perform an appendectomy.A sample of 8 appendectomies using the old method had a mean of 38 minutes with a variance of 36 minutes,while a sample of 10 appendectomies using the experimental method had a mean of 29 minutes with a variance of 16 minutes.For a right-tail test of means (assume equal variances),the test statistic is:
A) 3.814
B) 2.365
C) 3.000
D) 1.895

Question

Quizplus · Accepted Answer

The correct answer is A because the test statistic for a right-tail test of means with equal variances is calculated as (x̄1 - x̄2) / (s^2 / n1 + s^2 / n2)^1/2, where x̄1 and x̄2 are the sample means, s^2 is the pooled variance, and n1 and n2 are the sample sizes. Plugging in the given values, we get (38 - 29) / (36 / 8 + 16 / 10)^1/2 = 3.814.

Carver Memorial Hospital's Surgeons Have a New Procedure That They