Elephant Pregnancies. G. Wittemeyer et al. studied demographic data on African elephants living in Kenya in the article “Comparative Demography of an At-Risk African Elephant Population”

(PLOS ONE, Vol. 8. No. 1). Based on this study, we will assume that the time between pregnancies of the African elephant in Kenya, for elephants that have more than one calf, is normally distributed with mean 4.01 years and standard deviation 0.94 years. Determine the percentage of such times that are

a. less than 2 years.

b. between 3 and 5 years.