11.
(87+91+86+x)/4=90.
x=96.
13.
50×y > 130.
the lowest number could be 3, because 50×2=120, which is less than 130.
Answer:
The correct option is (b).
Step-by-step explanation:
If X
N (µ, σ²), then
, is a standard normal variate with mean, E (Z) = 0 and Var (Z) = 1. That is, Z
N (0, 1).
The distribution of these z-variate is known as the standard normal distribution.
The mean and standard deviation of the active minutes of students is:
<em>μ</em> = 60 minutes
<em>σ </em> = 12 minutes
Compute the <em>z</em>-score for the student being active 48 minutes as follows:

Thus, the <em>z</em>-score for the student being active 48 minutes is -1.0.
The correct option is (b).
Answer: 10
Step-by-step explanation: subtract 5 by 45 to get 40 then divide 4 to get 10
2 1/4+1 1/4=3 1/2
or 3.5 (3 and a half yards. )
8 over 9
= 8/9
= 8:9
Final answer: 8:9~