Can you provide more information? Where would the fire be? What type of fire?(wildfire, controlled fire) What is the purpose of the fire?
The answer is D because you just multiply the percent times 40 to get 12.
2x + 8.....factor = 2(x + 4)
Given:
μ = $3120, population mean
σ = $677, population standard deviation.
The population is normally distributed.
n = 20, sample size.
At the 95% confidence level, the confidence interval is

1.96(σ/√n) = 1.96(677/√20) = 296.71
Th confidence interval for the mean is
($2823.29, $3416.71)
Answer: ($2823.29, $3416.71)
3.2 divided by 0.4 would be 8