(Solved): Students in a fifth-grade class were given an exam. During the next 2 years, the same students were ...

Students in a fifth-grade class were given an exam. During the next 2 years, the same students were retested several times. The average score was given by the model \[ f(t)=88-15 \log (t+1), \quad 0 \leq t \leq 24 \] where \( t \) is the time in months. Round answers to \( \mathrm{I} \) decimal place. (a) What is the average score on the original exam? (b) What was the average score after 3 months? (c) After how many months does the average score drop below 71 ? months