Question

A population has a mean of 80 and a standard deviation of 7. A sample of 49 observations will be taken. The probability that the mean from that sample will be larger than 81 is

		0.1587
		0.0062
		0.0228
		0.0668

Answer 1

Population Mean = = 80

Standard deviation = = 7

Sample Size = n = 49

Let be the sample mean.

From Central Limit Theorem, we have,

We have to find,

                     (Value from attached z table)

The probability that the mean from that sample will be larger than 81 is 0.1587

z table :