Question

the average purchase per customer is 42 with a standard deviation of 4.36. using Chebysevs theorem what percentage of people will make a purchase between 54 and 30

I got 94.7 percent but i am unsure if its the correct answer can anyone verify this for me thanks

Answer 1

At least 86.7988889 is what I got.

(1-1/(12/4.36)^2
http://www.gseis.ucla.edu/courses/ed230a2/chebyshev.html

Answer 2

Thanks i see where i went wrong