Answer:
A. 7
Step-by-step explanation:
z ÷ (–7) = –1.
multiply each side by -7
z ÷ (–7)*-7 = –1.*-7
z = 7
Answer:
750 total people
Step-by-step explanation:
25 to 50 = 1/2
So: 250 x 2 = 500 men
500 + 250 = 750 total
Answer:
D.)
Step-by-step explanation:
because when you have numbers inside the parentheses, you have to multiply both of those numbers by the number to the right of the parentheses, not just the X.
Answer:
38%
Step-by-step explanation:
Given that X,the hours per week the music student practice follow a normal distribution.
X:N(8,4)
We have to find the percentage of students who practice between 6 and 10 hours.
6<x<10 implies converting to z
We know z = (x-mean)/sigma = (x-8)/4
Hence 6<x<10 is equivalent to (6-8/4)<Z<(10-8/4)
= |z|<0.5
From std normal table we find this area equals = 0.1915+0.1915
=0.3830 = 0.38 (rounded off)
Hence required percentage = 0.38x100 = 38%
