Answer:
The percentile for William is 76.97.
Step-by-step explanation:
1) Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Let X the random variable that represent the scors of a population, and for this case we know the distribution for X is given by:
Where
and 
2) Solution to the problem
We are interested in find the percentile for the score of 30 obtained by William. The best way to solve this problem is using the z score formula given by:

And z follows a normal standard distribution. We can find the z scor for the score X=30 like this:

And now we can find the probability using excel or a table, on this way:

And that means the 76.97 percentile since we have on the left of the score of 30, 0.7697 of the area on the left and 0.2303 of the area on the right.
So then the percentile for William is 76.97.
Answer:
54%
Step-by-step explanation:
total animals=27+23=50

No, it should not give exactly the right amount because numbers will have to be rounded because US dollars only go to the hundredths place making the final number slightly different than the exact value would be.
Square root of x^2 is x
square root of 144 is 12
(x-12) (x+12)
x=12 or x= -12
Answer: hypotenuse and leg of one right triangle
Step-by-step explanation:
The HL Postulate states that if the hypotenuse and leg of one right triangle are congruent to the hypotenuse and leg of another right triangle, then the two triangles are congruent.