Answer is 20 by plugging the 4 in the equation it equals 20
Answer:

Step-by-step explanation:
well, by using definition of tan of an angle
let the distance between Earth and shooting star is
.
since
,
then 
Answer:
Below in bold.
Step-by-step explanation:
The circumference is one dimensional so the ratio is the same as the radii,
1.5.
The areas are 2 dimensional so the ratio is 1.5^2 = 2.25.
Answer: The fox population decrease 1.298% every month.
Step-by-step explanation:
Since we have given that
Initial foxes = 170000
Every 7 months, the population loses 
So, we need to find the rate of change in population every month.
So, we will use "Unitary method":
So, In every month, the population loses 
So, the percentage would be

Hence, the fox population decrease 1.298% every month.
Let's analyse each option:
A.
Spending money means the money will decrease, so it would be represented by minus 32.
B.
Dropping a rock means its height will decrease, so minus 32 would fit better.
C.
The speed is decreasing, so minus 32 as well.
D.
The amount of books is increasing, so positive 32 fits better in this situation.
Therefore the correct option is D.