Question

The lifespan of laptop computers is skewed right with a mean of 5.5 years and a standard deviation of 3.5 years.

If simple random samples of 49 laptop computers are randomly selected, then what do we know about the distribution of the sample means? Choose one of the answers below:

A. the distribution is normal

B. the distribution is approximately normal

C. the distribution is exponential

Answer 1

49According to the "Central Limit Theorm",

If you have a population with mean μ and standard deviation σ and take sufficiently large random samples from the population, then the distribution of the sample means will be approximately normally distributed. This will hold true regardless of whether the source population is normal or skewed, provided the sample size is sufficiently large (usually n > 30).

Now, since here sample size (i.e. 49) is greater than 30, hence the distribution of the sample means will be:

B.) the distribution is approximately normal.