Chapter 1 - 1.7 - Linear Inequalities in One Variable - 1.7 Exercises - Page 139: 101a

It was during the years of 2005 and 2006.

$30\leq W\leq32$ $30\leq 0.903t+26.08\leq32$ $30-26.08\leq 0.903t+26.08-26.08\leq32-26.08$ $3.92\leq 0.903t\leq5.92$ $\frac{3.92}{0.903}\leq\frac{0.903t}{0.903}\leq\frac{5.92}{0.903}$ $4.341\leq t\leq6.556$ So, the solutions are: $t=5$ and $t=6$. It corresponds to the years 2005 and 2006.