Suppose that we randomly sample 40 light bulbs from a popula

Suppose that we randomly sample 40 light bulbs from a population that is skewed right with a mean of 10,000 hours and a standard deviation of 800 hours. We calculate the mean lifespan from this sample and record the value. We repeat this thousands of times.

1. Describe the shape of the distribution of the mean lifespan of light bulbs.  

Solution

The shape of the distribution of the mean lifespan of light bulbs is approximately normal.

i.e. bell shaped symmetrical unimodal.

The mean of samples follow a normal distirbution irrespective of the original distribution whether normal or skewed.