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Being a lit. student who doesn't even really know what all the math signs are, I have a question. It is probably super easy for anyone with q math iq higher than my room-temperature one.

The scores of students on ACT college entrance exams in recent years have had a mean of $\mu = 18.6$ and a standard deviation of $5.9$. Assuming that admitted students from a college have the same mean and standard deviation, find the probability that $50$ randomly chosen students would have a sample mean higher than $20$.

Thanks in advance!!

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closed as off-topic by Jonas Meyer, user91500, anomaly, Claude Leibovici, Najib Idrissi May 28 at 7:36

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2 Answers 2

Hint: the expected mean of the sample is the same as the mean of the parent distribution. The variance of the mean goes down as 1/n. So how many standard deviations high would the sample have to be? See Estimation of Parameters in the Wikipedia page

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Hint: the expected mean of the sample is the same as the mean of the parent distribution. The variance of the mean goes down as 1/n. So how many standard deviations high would the sample have to be?

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