Question

You wonder what is the average number of credits Le Moyne students take per semester. You speak with the Le Moyne registrar, and they tell you that Le Moyne students take an average of 17 credits per semester with a population standard deviation of 2.5 credits. We plan to take a sample of 49 students and ask each student how many credits they plan to take. Assume that the population mean is 17 credits and the populations standard deviation is 2.5 credits. What does the CLT say about the distribution of the sample mean of 49 students

Answer 1

The CLT says that the distribution is approximately normal, with mean of 17 credits and standard deviation of 0.3571 credits.

Explanation:

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean
`\mu` and standard deviation
`\sigma`, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
`\mu` and standard deviation
`s = (\sigma)/(√(n))`.

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Assume that the population mean is 17 credits and the populations standard deviation is 2.5 credits.

This means that
`\mu = 17, \sigma = 2.5`

What does the CLT say about the distribution of the sample mean of 49 students?

It is approximately normal.

The mean is 17.

Due to the sample of 49, n = 49, and the standard deviation is
`s = (2.5)/(√(49)) = 0.3571`

The CLT says that the distribution is approximately normal, with mean of 17 credits and standard deviation of 0.3571 credits.