Money earned by restaurant on Friday=$1073
Money earned by restaurant on Saturday=$1108
Let Money earned by restaurant on Sunday=$x
Average=$1000
Number of observation=3
⇒ 3× 1000=1073+1108+x
⇒3000= 2 181+x
⇒3000-2181=x
⇒x=819
The restaurant needs to earn on Sunday to average $1000 per day over the three-day period=$819