A payroll software firm has implemented a training program for new employees,

who will be providing in person service to their clients. The trainees undergo a

product knowledge test periodically during their training period. The average

percentage score on this test, $P(t),$ as function of time, $t$ in weeks of training, is

given by the following logistic growth function:

$P(t)=\frac{100}{1+9e^{-0\mathrm{.}5t}}$

A minimum score of $85\%$ is expected before an employee can be considered to

have completed their training and capable of providing service to clients.