A sample of n = 4 scores is selected from a normal population with μ = 30 and σ = 8.The probability of obtaining a sample mean greater than 34 is equal to the probability of obtaining a z-score greater than z = 2.00.

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Quizplus · Accepted Answer

To find the probability of obtaining a sample mean greater than 34, we use the formula for the standard error of the mean (σM = σ / √n) and then calculate the z-score for the sample mean of 34. With σ = 8 and n = 4, the standard error σM = 8 / √4 = 4. The z-score for a sample mean of 34 is (34 - 30) / 4 = 1. A z-score of 1 does not equal a z-score of 2.00, thus the probabilities are not equal.

A Sample of N = 4 Scores Is Selected from a Normal