Question test scores are normally distributed with a mean of

Question

test scores are normally distributed with a mean of 75 and a standard deviation of 13. A sample of 120 student tests was randomly selected and found to have a sample mean of 79 and standard deviation of 15.

Answer the following questions based on this scenario.

Symbol

Numeric Value

What is the population mean?

What is the population standard deviation?

What is the sample mean?

What is the sample standard deviation?

What is the sample size?

When samples of 120 tests are selected from this population, what is the mean of the sampling distribution of sample means?

When samples of 120 tests are selected from this population, what is the standard deviation of the sampling distribution of sample means?

Explain whether the sampling distribution is normal.

Solution

What is the population mean?
u = 75     
What is the population standard deviation?
sigma = 13     
What is the sample mean?
x = 79     
What is the sample standard deviation?
s = 15
What is the sample size?
n= 120