Hogwarts need to order more magic wands with a length of 20 cm. Since all magic wands are unique, the length varies normally with an average value of 19.7 cm and a standard deviation of 0.4 cm. What percentage of the wands are expected to be shorter than 19.3 cm?

Guest May 7, 2021

#1**+1 **

Average (mean) = 19.7 cm ONE standad deviation (0.4) below the mean is 19.3 cm

How many wands are below one standard deviation?

from z-score table z = -1 equates to .1587 or 15.87%

ElectricPavlov May 7, 2021