#### Answer

The equivalent temperatures are, respectively, 47.8 $^{\circ}$C and -8.3 $^{\circ}$C.

#### Work Step by Step

T($^{\circ}$C) = $\frac{5}{9}$ * [T($^{\circ}$F) - 32]
T($^{\circ}$C) at 118 $^{\circ}$F:
T($^{\circ}$C) = $\frac{5}{9}$ * [118 - 32]
T($^{\circ}$C) = $\frac{5}{9}$ * [86]
T($^{\circ}$C) = 47.7777778 $^{\circ}$C
Rounding to 3 significant figures gives 47.8 $^{\circ}$C
T($^{\circ}$C) at 17 $^{\circ}$F:
T($^{\circ}$C) = $\frac{5}{9}$ * [17 - 32]
T($^{\circ}$C) = $\frac{5}{9}$ * [-15]
T($^{\circ}$C) = -8.33333333 $^{\circ}$C
Rounding to 2 significant figures gives -8.3 $^{\circ}$C
So the equivalent temperatures are, respectively, 47.8 $^{\circ}$C and -8.3 $^{\circ}$C.