68% of the zebras have lifespan between 16.6 and 24.4 years.
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 20.5 years
Standard Deviation, σ = 3.9 years
Empirical Formula:
Almost all the data lies within three standard deviations of the mean for a normally distributed data.
About 68% of data lies within one standard deviation of mean
About 95% of data lies within two standard deviation of the mean.
About 99.7% of data lies within three standard deviation of the mean.
We have to find the percentage of Zebras having lifespan between 16.6 and 24.4 years.
We can write:
16.6=20.5-3.9=μ-σ
24.4=20.5+3.9=μ+σ
Thus, by empirical rule around 68% of data lies within one standard deviation from the mean.
Thus, 68% of the zebras have lifespan between 16.6 and 24.4 years.
