In a left-tailed test comparing two means with unknown variances assumed to be equal,the test statistic was t = -1.81 with sample sizes of n₁ = 8 and n₂ = 12.The p-value would be: A) between .025 and .05. B) between .01 and .025. C) between .05 and .10. D) Must know $\alpha$ to answer.

Question

Quizplus · Accepted Answer

To find the p-value for a t-test with equal unknown variances, we need to look up the value of t on a t-distribution table with degrees of freedom equal to that of the pooled sample (df = n1 + n2 - 2 = 8 + 12 - 2 = 18). From a table, we find that the area to the left of a t-value of -1.81 with 18 degrees of freedom is approximately 0.045. Since this is a left-tailed test, this area represents the p-value. Therefore, the p-value is between .025 and .05.

In a Left-Tailed Test Comparing Two Means with Unknown Variances α\alphaα

In a Left-Tailed Test Comparing Two Means with Unknown Variances $\alpha$