The tutor follows his earlier post with an implication about holiday weight gain.

In yesterday’s post I discussed the surprise that perhaps mean holiday weight gain is no more than a pound; furthermore, I estimated its standard deviation at 3.125lbs. Given that information, what percentage of people gain no weight at all?

Given mean μ=1 and σ=3.125, we can calculate the z-score for 0:

z=(x-μ)/σ = (0-1)/3.125=-0.32

Looking at the standard normal table, z=-0.32 corresponds to 0.3745. Given our assumptions, about 37% of people gain no weight during the holidays. If you’re one of those, congratulations!

HTH:)

Source:

Harnett, Donald L. and James L. Murphy. Statistical Analysis for Business and Economics. Don Mills: Addison-Wesley, 1993.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.