help me solve part e.

Students in a zoology class took a final exam. They took equivalent forms of the exam at monthly intervals thereafter. After t months, the average score S(t), as a percentage, was found to be given by the following equation, where t2 0. Complete parts (a) through (e) below. S(t)=77 - 12 In (t+ 1), Osts80 ===) a) What was the average score when they initially took the test? The average score was 77 %. (Round to one decimal place as needed.) b) What was the average score after 4 months? The average score after 4 months was 57.7 %. (Round to one decimal place as needed.) c) What was the average score after 24 months? The average score after 24 months was 38.4 %. (Round to one decimal place as needed.) d) Find S(t). 12 S'()= -a7 e) Find S'(4) and S'(24), and interpret the meaning of these numbers. s$'(4)= [ |. which means that after 4 months, the average score is by [| points a month and S'(24)= [ |. which means that after 24 months, the average score is by [| points a month. (Type integers or decimals.)