A sample of n = 25 scores is selected from a population with μ = 50 and σ = 10.The probability of obtaining a sample mean greater than 55 is p = 0.3085.

Question

Quizplus · Accepted Answer

The probability of obtaining a sample mean greater than 55 would typically be calculated using the standard error of the mean and the Z-score formula. Given the population standard deviation (σ = 10) and the sample size (n = 25), the standard error (σM) would be σ/√n = 10/√25 = 2. The Z-score for a sample mean of 55 would be (55 - μ) / σM = (55 - 50) / 2 = 2.5. The probability associated with a Z-score of 2.5 is less than 0.3085, indicating that the original statement likely miscalculated the probability.

A Sample of N = 25 Scores Is Selected from a Population