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) = 86 – 19 log(t + 1), 0

Extracted text: 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) = 86 – 19 log(t + 1), 0 <>< 24="" where="" t="" is="" the="" time="" in="" months.="" round="" answers="" to="" at="" least="" 1="" decimal="" point.="" (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="">