Given that on one section of the sat the mean is 500 and the standard deviation is 100, what is the approximate probability of a student scoring 400 or lower or 500 or higher on the test?

We are to find for the probability when X≤400 or X≥500

We use the z score formula: z = (x – u) / s

when X≤400, the z is:

z = (400 – 500) / 100 = - 1

when X≥500, the z is:

z = (500 – 500) / 100 = 0

SO from the standard probability tables, the probability at:

P (z ≤ -1 or z ≥ 0) = 0.6587

41*67/2=1373.5

step-by-step explanation:

i just used a calculator

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0