Answer
Estimate=90 ft
Exact=89 ft
Work Step by Step
Estimate:
15$\frac{1}{2}$$\approx$16
18$\frac{3}{4}$$\approx$19
24$\frac{1}{4}$$\approx$24
30$\frac{1}{2}$$\approx$31
16+19+24+31=90
Exact:
15$\frac{1}{2}$+18$\frac{3}{4}$+24$\frac{1}{4}$+30$\frac{1}{2}$
15$\frac{2}{4}$+18\frac{3}{4}$+24\frac{1}{4}$+30\frac{2}{4}$
87\frac{8}{4}$
89