Since about 95% of a normal distribution falls within two standard deviations of the mean

, it follows that 5% lie outside this range, with 2.5% lying to either side of it.This means

, with the remaining 2.5% lying above

.
This means for a score to belong in the top 2.5%, it's corresponding z-score must be higher than 2.
Fred scores 13.1 on the test. The corresponding z-score is

which is barely higher than 2, but high enough to earn that certificate.
![\sqrt[3]{27x-81} -5](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B27x-81%7D%20-5)
Let's start by simplifying the expressions inside the root. Use distributive property.
![\sqrt[3]{27(x-3)} -5](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B27%28x-3%29%7D%20-5)
Isolate the square root terms.
![\sqrt[3]{27} \sqrt[3]{x-3}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B27%7D%20%5Csqrt%5B3%5D%7Bx-3%7D)
Simplify:
![3\sqrt[3]{x-3} -5](https://tex.z-dn.net/?f=3%5Csqrt%5B3%5D%7Bx-3%7D%20-5)
The graph looks of this function, if we assume that
![f(x) = 3\sqrt[3]{x-3} -5](https://tex.z-dn.net/?f=f%28x%29%20%3D%203%5Csqrt%5B3%5D%7Bx-3%7D%20-5)
It looks like a cubic root function that has the domain and range of all real numbers and passes through
and 
AA, because if you know 2 angles then you know the 3rd angle, and if all three angles are the same in both triangles, no matter how big the sides are the triangles will always be similar.
(you and 3 friends so we have 4 person
<span>The group plans to ride each water ride twice.</span>
so for each person we will pay 2(4.5+4+3.5)=2*12=24$
and for 4 person 24*4=96$
100-96=4$
Answer: 4$)
but looking on gaven answers i understood that each person pay only for himself!
so you paid 24$ and will get back 100-24=76$
Answer: 76$