Distributions and life expectancy: Researchers have reported that the projected
ID: 3051987 • Letter: D
Question
Distributions and life expectancy: Researchers have reported that the projected life expectancy for people diagnosed with human immunodeficiency virus (HIV) and receiving antiretroviral therapy (ART) is 24.2 years (Schackman et al., 2006). Imagine that the researchers determined this by following 250 people with HIV who were receiving ART and calculating the mean. If the distribution of the population were skewed, would the distribution of scores likely be skewed or approximately normal and why?
A sample of 250 people would be dominated by the central limit theorem, so the sample would be normally distributed.
A distribution of scores from 250 people should closely resemble the original population, so the sample distribution should be skewed.
A sample of 250 people will be more normal than the distribution it came from, but it may still remain slightly skewed.
It is impossible to know what the shape of the sample would be.
Explanation / Answer
HERE As we are taking above distribution of scores and not their mean
therefore correct option is:
A distribution of scores from 250 people should closely resemble the original population, so the sample distribution should be skewed.
(Note for sample mean option 1 would have been correct)