Answer:
Rate of Decay = 8%
Step-by-step explanation:
The decay formula is:
[tex]F=P(1-r)^t[/tex]
Where F is the final value (here, it is given as "Y")
P is the initial value (here, given as 20,000)
r is the rate of decay (what we need to find)
t is the time (given as 2)
Comparing both the equations:
[tex]F=P(1-r)^t\\Y=20,000(0.92)^2[/tex]
We see that:
1 - r =0.92
We solve for "r":
1 - 0.92 = r
0.08 = r
The rate of decay is 0.08, as a percentage, we need to multiply by 100, so we have:
0.08 * 100 = 8%
Rate of Decay = 8%