To solve this problem, we make use of the z statistic.
What we have to do here is to find for the z score using the given data and
from the standard probability tables for z, we locate the proportion of the
fish longer than 12 inches.
The formula for calculating the z score is:
z = (x – μ) / σ
where,
x = the sample value = 12 inches
μ = the sample mean = 11 inches
σ = 2 inches
so,
z = (12 – 11) / 2
z = 1 / 2
z = 0.5
Since we are looking for the values greater than 12, so
this is a right tailed test. Using the tables, the value of p at this value of
z is:
p (z = 0.5) = 0.3085
Therefore there is a 30.85% probability that the fish is
longer than 12 inches.
Step-by-step explanation:
7. x/4=-2.5
x = -2.5/4= 5/8
8. -22=n/2
n = -22×2 =-44
9. 1/3z = -5
z = -5×3 =-15
10. -1/4x=5/2
-2=5×4x
-2=20x
x=-20x/2=-10
Prob of selected students times prob of selecting boys times prob of selecting 3 boys
total students = 15b + 30g = 45 students
1. 10s/45t = 0.22
2. 15b/45t = 0.33
3. 3b/15b = 0.2
0.22×0.33×0.2=0.0148
1.48%
I'm not sure 100%... double check answer please
We can simplfiy to be 
.
We know that 
is 10 and 
is i, so the answer is 10i, or D.
