**An efﬁciency study of the morning shift at a certain factory indicates thatan average worker arriving on the job at 8:00A.M. will have produced Q(t) = -t^3 + 9t^2 + 12t units, t hours later.**

**a) Use calculus to estimate the change in theworker’s rate of production between 9:00 and9:06A.M**

**b) Compute the actual change in the worker’s rate of production between 9:00 and 9:06A.M**

**Answer:**