<span>-4(X+2)-1/2(2X-6)
-4*x + -4*2 - (1/2)*2x -(1/2)*(-6)
-4x - 8 - x + 3
-4x - x - 8 + 3
-4x - x + 3 - 8
-5x - 5
</span>
Answer:
2614.33333333
Step-by-step explanation:
So we are given the mean and the s.d.. The mean is 100 and the sd is 15 and we are trying the select a random person who has an I.Q. of over 126. So our first step is to use our z-score equation:
z = x - mean/s.d.
where x is our I.Q. we are looking for
So we plug in our numbers and we get:
126-100/15 = 1.73333
Next we look at our z-score table for our P-value and I got 0.9582
Since we are looking for a person who has an I.Q. higher than 126, we do 1 - P. So we get
1 - 0.9582 = 0.0418
Since they are asking for the probability, we multiply our P-value by 100, and we get
0.0418 * 100 = 4.18%
And our answer is
4.18% that a randomly selected person has an I.Q. above 126
Hopes this helps!