Question

2) Students in an English class took a final exam. They took equivalent forms of the
exam at monthly intervals thereafter. The average score S(t), in percent, after t months
was found to be given by
S(t) = 68 − 20 log (t + 1), t ≥ 0.
a) What was the average score when they initially took the test, t = 0?
Answer:
Show your work in this space:
b) What was the average score after 14 months?
Answer:
Show your work in this space:
c) After what time t was the average score 40%?
Answer:
Show your work in this space:

Answer 1

a) just plug t=0 into the equation
s(0)=68-20log(1)
=68
b) t=14
s(14)=68-20log(15)
=44.47
C)40=68-20log(t+1) Solve for t
28=20log(t+1)
1.4=log(t+1) Raise both sides to the 10th to remove the log
10^1.4=10^(log(t+1))
25.1159=t+1
t=24.1189

Answer 2

Thank you so much