so hmmm from 21 1/4 to 37, let's check the difference, to see how many feet is that.
[tex]\bf 37-21\frac{1}{4}\implies 37-\cfrac{21\cdot 4+1}{4}\implies 37-\cfrac{85}{4}\impliedby LCD~is~4
\\\\\\
\cfrac{148-85}{4}\implies \cfrac{63}{4}[/tex]
so hmmm now, its growth rate is [tex]\bf 1\frac{3}{4}\implies \cfrac{1\cdot 4+3}{4}\implies \cfrac{7}{4}[/tex]
so.... the tree grows 7/4 in 365 days( a year ), how many days does it take it to get to 63/4 feet?
[tex]\bf \begin{array}{ccll}
\stackrel{growth}{feet}&\stackrel{time}{days}\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
\frac{7}{4}&365\\\\
\frac{63}{4}&d
\end{array}\implies \cfrac{\frac{7}{4}}{\frac{63}{4}}=\cfrac{365}{d}\implies \cfrac{7}{4}\cdot \cfrac{4}{63}=\cfrac{365}{d}
\\\\\\
\cfrac{28}{252}=\cfrac{365}{d}\implies d=\cfrac{252\cdot 365}{28}\implies d=\cfrac{91980}{28}\implies \boxed{d=3285}[/tex]