<span>The correct answer is C.
This is because you need a first term that equals 14.5, for when n = 1.
So, you can determine this by using n=1 in each equation until you find one that works. When you stick 1 in for n in answer C, it looks like this:
18 - 3.5n
18 - 3.5(1)
18 - 3.5
14.5 ---> This is the answer that we are looking for.
This will not work for any of the other options. </span>
Answer:
a =
b = 12
c =
Step-by-step explanation:
Since the triangles are right triangles with 60 and 45 degree angles, their side lengths follow special triangles.
A 45-45-90 right triangle has side lengths .
A 30-60-90 right triangle has side lengths .
Starting with the top triangle which has a 60 degree angle, its side length 6 corresponds to a side length of 1 in the special triangle. It is 6 times bigger so its remaining sides will be 6 times bigger too.
Side a corresponds to side length . Therefore, .
Side b corresponds to side length 2, b = 2*6 = 12.
The bottom triangle has a 45 degree angle, its side length b= 12 corresponds to . This means was multiplied by . This means that side c is .
I believe the correct answer is 426, but i could be wrong, so my apologies.
The 85th percentile is the cutoff time
such that
In other words, the 85th percentile refers to the time needed to belong to the top 15% of the distribution; more generally, the
percentile is the top
of the distribution.
Anyway, to find this value of
, transform
to a random variable
with the standard normal distribution using
where
is the mean of
and
is the standard deviation of
.
Here
is used to denote the z-score corresponding to the cutoff time
. Referring to a z-score table, you find that this occurs for
. So,