If you choose 10 swimmers and 4 are Stingrays, you can say that Stingrays make up roughly 40% of the swimmers. If 20 Stingrays make up 40% of all the swimmers, we just have to find what number 20 is 40% of. That’s easy enough by cross multiplication:
20/x = 40/100
20/x = 4/10
20/x = 2/5
x = 50.
Double check by multiplying 50 * 0.4. Since 50 * 0.4 = 20, we know we have the right answer. There are about 50 swimmers on this team.
By "density" I assume you mean "probability density function". For this to be the case for

, we require

Since

you have

which means
Answer:
DF = 14
Step-by-step explanation:
Andrew was wrong in the assumption that DE = EF
Segments of tangents to a circle from the same external point are congruent
That is
EF = FG = 8
Then
DF = DE + EF = 6 + 8 = 14
Answer:
A value, or values, we can put in place of a variable (such as x) that makes the equation true.
Example: x + 2 = 7
When we put 5 in place of x we get: 5 + 2 = 7
5 + 2 = 7 is true, so x = 5 is a solution