Capacities of the cranial cavities?

if the capacities of the cranial cavities of a certain population are apprximately normally distributed with a mean of 1400cc and a standard deviation of 125, find the probability that a randomly selected person from the given population will have a cranial cavity capacity greater than 1450cc

Capacities of the cranial cavities?
Start with the equation for a Gaussian probability distribution (random distribution)





f(x) = {e^-[(x-u)^2] / 2s^2} / [s * (2*pi)^0.5]





where


x = the cranial capacity in cc


u = the mean of the sample (1400 cc)


s = standard deviation = 125


pi = 3.14159





1) Integrate this equation and find the area under the curve from -infinity to +infinity


Call this a1





2) integrate the equation from 1450 cc to +infinity


call this a2





The ratio of the answers from 2 and 1 equal the probability that the cranial capacity exceeds 1450





p = a2/a1





Hope this helps,





-Guru