Question

A national survey by Gallup interviewed a random sample of 1014 adults and found that they had consumed on average 4.2 alcoholic beverages in the past seven days. The distribution of the number of alcoholic beverages in the sample was clearly right-skewed. Q10.13 Points What would most likely be the shape of the distribution of the number of alcoholic beverages consumed in the past seven days in the entire American adult population

Answer 1

Approximately normal

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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean
`\mu = p` and standard deviation
`s = \sqrt{(p(1-p))/(n)}`

In this question:

As the sample size is above 30, even though the underlying distribution is right-skewed, the shape of the sampling distribution of the sample means will be approximately normal.