SOLUTION: Students in a fifth-grade class were given an exam. During the next 2 years, the same students were retested several times. The average scores was given by the model g(t)=90-15log(

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Students in a fifth-grade class were given an exam. During the next 2 years, the same students were retested several times. The average scores was given by the model g(t)=90-15log(      Log On


   

Question 1179101: Students in a fifth-grade class were given an exam. During the next 2 years, the same students were retested several times. The average scores was given by the model g(t)=90-15log(base:10)(t+1), 0 <=t<=24
Where t is the time in months.
A) what is the average score on the original exam?
B) what was the average score after 6 months?
C what was the average score after 18 months?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

g%28t%29=90-15log%2810%2C%28t%2B1%29%29, 0+%3C=t%3C=24

A) what is the average score on the original exam?

that is when t=0
Average score is
+g%280%29+=+90+-+15log%2810%2C%280%2B1%29%29
+g%280%29=+90+-+15log%2810%2C%281%29%29+
+g%280%29=+90+-+15%2A0+
+g%280%29=+90+


B) what was the average score after 6 months?
that is when t=6
Average score is
+g%286%29+=+90+-+15log%2810%2C%286%2B1%29%29
+g%286%29=+90+-+15log%2810%2C%287%29%29+
+g%286%29=+90+-+15%2A0.8451
+g%286%29=+77.32


C) what was the average score after 18 months?

that is when t=18
Average score is
+g%2818%29+=+90+-+15log%2810%2C%2818%2B1%29%29
+g%2818%29=+90+-+15log%2810%2C%2819%29%29+
+g%2818%29=+90+-+15%2A1.2787536
+g%2818%29=+70.82