A recent study found that the life expectancy of a people living in Africa is normally distributed with an average of 53 years with a standard deviation of 7.5 years. If a person
In Africa is selected at random, what is the probability that the person will die before the
Age of 65?

Question

Quizplus · Accepted Answer

To find the probability that a person will die before the age of 65, we use the Z-score formula: Z = (X - μ) / σ, where X is the value of interest (65 years), μ is the mean (53 years), and σ is the standard deviation (7.5 years). Plugging in the values, we get Z = (65 - 53) / 7.5 = 12 / 7.5 = 1.6. Looking up a Z-score of 1.6 in the standard normal distribution table gives us a probability of approximately 0.945 or 94.5%.

A Recent Study Found That the Life Expectancy of a People