Answer
$|x_1-123|\le 25$
$|x_2-21|\le 5$
Work Step by Step
Step 1. Given $98ft/sec\le x_1 \le 148ft/sec$, find the mean value as $\frac{98+148}{2}=123$
Step 2. Half of the range is $\frac{148-98}{2}=25$, thus we can write $|x_1-123|\le 25$
Step 3. Given $16ft/sec\le x_2 \le 26ft/sec$, find the mean value as $\frac{16+26}{2}=21$
Step 4. Half of the range is $\frac{26-16}{2}=5$, thus we can write $|x_2-21|\le 5$
