The population of IQ scores forms a normal distribution with a mean of μ= 100 and a standard deviation of σ= 15. What is the probability of obtaining a sample mean greater than M = 95, a. for a random sample of n = 9 people? b. for a random sample of n = 25 people?
Added by Karen C.
Step 1
For a sample size of n = 9, the standard error (SE) is: SE = σ / √n = 15 / √9 = 15 / 3 = 5 Now, we can find the z-score for M = 95: z = (M - μ) / SE = (95 - 100) / 5 = -1 For a sample size of n = 25, the standard error (SE) is: SE = σ / √n = 15 / √25 = 15 / Show more…
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