Answer:
-Exponential Decay
-Decay factor is (1-0.05)
Step-by-step explanation:
-Given that the number decreases by a defined rate each year from the initial size by 5%,
-This is an exponential decay function of the form:

Where:
is the quantity/size after time t
is the initial size
is the rate of decay
-Our function can the be written as

Hence, the decay rate/factor is 0.05
#Alternatively
The exponential decay can be of the form:

Where:
y is the size at time x, a is the initial size, x is time and b is the decay factor.
b is of the form 

Hence, the decay factor is (1-0.05)
Answer: -21, -33, -45
Step-by-step explanation:
each next number is being subtracted by 12 so
The money is a lot so it would be c
The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.