Time-spent using e-mail per session

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Reference no: EM13103849

Time spent using e-mail per session is normally distributed, with μ = 8 minutes, and σ = 2 minutes. If you select a random sample of 25 sessions,

a) What is the probability that the sample mean is between 7.8 and 8.2 minutes?

b) What is the probability that the sample mean is between 7.5 and 8 minutes?

c) If you select a random sample of 100 sessions, what is the probability that the sample mean is between 7.8 and 8.2 minutes?

Reference no: EM13103849

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