Given that a population is normally distributed with a mean of and a standard deviation of
For a sample of size n from normally distributed population, the sampling distribution of the sample mean is also normally distributed with mean and standard deviation of .
Therefore, the probability can be obtained using the Excel formula NORMDIST (x, mean, standard deviation, 1) as below:
The probability is very high so it cannot be unusual for the mean of sample 20 to be 115 or more.
Get Answers For Free
Most questions answered within 1 hours.