We have the following linear model:
[tex]y=11x+12[/tex]now, if 'x'is the number of years since 1990, then for 1997, we have that 7 years has passed, then x = 7, and the model would be:
[tex]\begin{gathered} x=7 \\ \Rightarrow y=11(7)+12=77+12=89 \\ y=89 \end{gathered}[/tex]therefore, there could be 89 retail stores in 1997