Questions: The size of a rat population at the bay area of a certain city grows at a rate of 5% monthly. If there are 20 rats currently, find how many rats (rounded to the nearest whole) should be expected in 18 months. Use y=200(2.7)^(0.05 t), and let t be 18 months.
y= rats.
Transcript text: The size of a rat population at the bay area of a certain city grows at a rate of $5 \%$ monthly. If there are 20 rats currently, find how many rats (rounded to the nearest whole) should be expected in 18 months. Use $y=200(2.7)^{0.05 t}$, and let t be 18 months.
$y=$ $\square$ rats.
Solution
Solution Steps
Step 1: Convert the growth rate into a decimal
The growth rate given is 5, which as a decimal is 0.05.
Step 2: Identify the parameters
Initial population size (P_0): 20
Base growth factor (r): 2.7
Growth rate (g) as a decimal: 0.05
Time period in months (t): 18
Step 3: Substitute the values into the formula
Using the formula $P(t) = P_0 \cdot r^{gt}$, we substitute the values to get $P(t) = 20 \cdot 2.7^{0.05 \cdot 18}$
After calculation, the future population size is 48.894.
Step 4: Round the result
Rounding the result to 0 decimal places, we get 49.
Final Answer:
The future population size after 18 months is approximately 49.