Answer:
By the Central Limit Theorem, the mean is 78, the standard deviation is and the shape is approximately normal.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean and standard deviation
, the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean
and standard deviation
.
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Mean of 78 and a standard deviation of 6
This means that
Samples of n:
This means that the standard deviation is:
What are the mean, standard deviation, and shape of the distribution of x-bar for n?
By the Central Limit Theorem, the mean is 78, the standard deviation is and the shape is approximately normal.