C. The square root of 144
Hi my name is Fabian and 69% because 69 is a man which is multi colour hair
The normal distribution curve for the problem is shown below
We need to standardise the value X=405.5 by using the formula


We now need to find the probability of z=0.32 by reading the z-table
Note that z-table would give the reading to the left of z-score, so if your aim is to work out the area to the right of a z-score, then you'd need to do:

from the z-table, the reading

gives 0.6255
hence,

The probability that the mean weight for a sample of 40 trout exceeds 405.5 gram is 0.3475 = 34.75%
Question 5:
x/3=6
x=3(6)
x=18
Question 4:
2.3k=4.83
k=4.83/2.3
k=2.1
Question 6:
y=3/4-1/2
y=1/4
Question 2:
8r=24
r=3
Hope this helps!! :)