At least 75​% of the observations lie between which two​ values?

Question

A quantitative data set has mean 22 and standard deviation 3.

Apply​ Chebyshev's rule 

Answer 1

Given, µ = 22 and σ =3

From Chebyshev's Theorem,

1 - 1/k^2 = .75 => k = 2

Since observation lies between ( µ-kσ, µ+kσ) because they are symmetric around the mean.

i.e,  (22-2*3, 22+2*3) => (16,28)

So the values are 16 and 28