A population of insects in a greenhouse is modeled by the function P(t), where t is the number of days after the start of observation and P(t) is measured in hundreds of insects. If P′(7)=−3, which of the following is the best interpretation of this value?
a) The population increases by about 300 insects per day at t=7 days.
b) The population decreases by about 300 insects per day at t=7 days.
c) The population decreases by about 3 insects per day at t=7 days.
d) On average, the population has decreased by about 300 insects per day during the first 7 days.