Answer
a) 3.8
b) 3.765
Work Step by Step
To round to the nearest tenth, inspect the hundredths digit. If 5 or greater, round up.
$3.7\underset\uparrow654$
round up
$3.7654\approx3.8$
To round to the nearest thousandth, inspect the ten-thousandths digit. If 5 or greater, round up.
$3.765\underset\uparrow4$
do not round up
$3.7654\approx3.765$