The mean age of all high school teachers in New York state is 50 years and the standard deviation is 7 years.According to Chebyshev's theorem,the percentage of teachers in New York who are 25.5 to 74.5 years old is at least:
A)91.84
B)83.67
C)87.34
D)93.84

Question

Quizplus · Accepted Answer

Chebyshev's theorem states that at least (1 - 1/k^2) of the data lies within k standard deviations of the mean. Here, k = (74.5 - 50) / 7 = 3.5. So, at least (1 - 1/3.5^2) = 91.84% of the data lies within this range.

The Mean Age of All High School Teachers in New