Central Limit Theorem Application

Question

The life expectancy of a species of naked mole rat is normally distributed with a mean of $$\mu=21$$ years and a standard deviation of $$\sigma=3$$ years. For a random sample of size $$n=40$$, which of the following correctly uses the central limit theorem to find the probability that the sample mean life expectancy is between $$20$$ and $$22$$ years?

Accepted Answer

Using $$normalcdf(20, 22, 21, (3/\sqrt{40}))$$ to compute the probability.

Answer

Applying the empirical rule without converting to a z-score.

Answer

Using $$normalcdf(20, 22, 21, 3)$$ without adjusting the standard deviation.

Answer

Using $$invNorm(0.5, 21, (3/\sqrt{40}))$$ to find the sample mean corresponding to the median.

Central Limit Theorem Application

Question Leaderboard