The mean age of all high school teachers in New York state is 41 years and the standard deviation is 6 years.According to Chebyshev's theorem,the percentage of teachers in New York who are 23 to 59 years old is at least:
A)88.89
B)77.78
C)84.39
D)90.89

Question

Quizplus · Accepted Answer

Chebyshev's theorem states that at least (1 - 1/k^2) of the data falls within k standard deviations of the mean. Here, 23 to 59 years is 3 standard deviations from the mean (41 ± 3*6). So, at least (1 - 1/3^2) = 88.89% of the data falls within this range.

The Mean Age of All High School Teachers in New