IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Using the empirical rule, determine the interval that would represent the middle 95% of IQ scores.

mrbilldoesmath!

answer: a parabola

steps:

(x-1)(x+4)   = x(x+4) - 1(x+4) = (x^2 + 4x) - (x+4)

                = x^2 +4x -x -4   = x^2 +3x -4

which is a parabola

mrb

umm you say your want to . but you do know that this is the mathematics.  

o~o