Suppose a population has a mean of 870 and a variance of 8,100.If a random sample is size 36 is drawn from the population, the probability that the sample mean is between 840 and 900 is ___.
A)0.9544
B)0.6826
C)0.8185
D)0.5899
E)0.0897

Question

Quizplus · Accepted Answer

The standard deviation of the sample mean is the population standard deviation divided by the square root of the sample size, which is 90/6 = 15. Using the standard normal distribution, the probability that the sample mean is between 840 and 900 is approximately 0.9544.

Suppose a Population Has a Mean of 870 and a Variance