Letter D because you need to multiply all the letters of the alfabet (36) and multiply 36 by 1000 and then divide the answer by 100 and you get the letter D
This is the concept of functions. We are required to calculate for the total cost of tickets if 27, 39 and 43 people attended a concert whose cost was represented by C=10n+26.
To solve for this we substitute the each values in the function as follows;
When n=27
C(27)=10*27+26=296
When n=39
C(39)=10*39+26=416
When n=43
C(43)=10*43+26
=456
The 70th percentile is the same as the cutoff recovery time

such that every point above this time falls in the longest 30%, i.e.

Transform to the standard normal distribution:

where

is the z-score corresponding to the cutoff time

, which is approximately

. Solve for

:
If they are perpendicular, they form a right angle. For example, this is perpendicular:
I_
If likes are parallel, they run along each other, never meeting. For example, these two lines are parallel:
___
___
Hope this helps!