In: Statistics and Probability
In a certain distribution, the mean is
40
with a standard deviation of
5
At least what fraction of the numbers are between the following pair of numbers?
30
and 50
Solution:
= 40
= 5
According to Chebyshevs's theorem , the minimum probability of "between - k and + k " is 1 - (1/k2)
So , minimum probability of "between - 2 and + 2 " is 1- (1/22 ) i.e. 3/4
"Between 30 and 50 " = "between 40 - (2*5) and 40 + (2*5)" = "between - 2 and + 2 "
So , answer is 3/4 i.e 0.75
At least 3/4 of the numbers are between the following pair of numbers 30 and 50