Suppose the time he spent surfing the website per day is normally distributed, µ = 8 minutes and σ = 2 minutes. If you select a random sample of 4 sessions, What is the probability that the sample...

 Suppose the time he spent surfing the website per day is normally distributed, µ = 8 minutes and σ = 2 minutes. If you select a random sample of 4 sessions,

What is the probability that the sample mean is less than 8 minutes?

What is the probability that sample mean is between 8 and 10 minutes?

If you select a random sample of 16 sessions, what is the probability that a as sample mean is between 8 and 9 minutes?

Explain the differences in the results of (b) and (c).