Answer
$\$82.86$
Work Step by Step
To figure out the average daily amount of tips, we must divide the total amount of tips by $7$, the number of days that the waiter worked. To figure out how much money the waiter earned in tips for the week, we add up the amount of tips he earned on each individual day: $\$90+\$40+\$50+\$40+\$60+\$120+\$180=\$580$. Next, we divide by $7$: $\$580\div7\approx\$82.86$
