Percent Error
What is the formula for percent error?
difference of actual and estimated divided by actual
Find the percent change.
Original cost: $100
New cost: $59
(59-100)/100 = -41/100 = -.41= -41%
41% decrease
$50 Watch: 6% sales tax
$53
A car salesman sells a car worth $17,500 with a 9% commission rate. How much commission did he earn?
What is $1575
Xavier buys T-shirts for $6 each and marks up the price by 45%. How much profit does Xavier make from each T-shirt sold?
$2.70
A measurement was 34.5 m. The accepted value is 36.7 m, This is the percent error of the measurement?
5.99% error
Original price $0.50 New price $0.65
What is 30%
$45 Calculator: 4% sales tax
$46.80
How much would you tip your hairdresser if your haircut costs $25 and you want to tip her 15%?
What is $3.75
A store advertises a 20% markdown on a dishwasher that normally sells for $952. Find the price on sale.
$761.60
Eva estimates that 475 songs will fit on her MP3 player. The actual amount of songs that fit is 380. Find the percent of error.
25%
Original weight 110lb New weight 132lb
What is 20%
$110 Bike: 5% sales tax
$115.50
Bobby earned $26 commission with a 4% commission rate. How much did he sell?
What is $650
Best Buy got a new 70'' flat screen TV for $130. The TV is marked up 40%. What is the new cost?
What is $182.00
Tray estimates that a new car will cost him $11,300. It actually cost him $10,800. What is the percent of error rounded to the nearest tenth?
4.6%
Original number 70 New number 98
What is 40%
$59.90 Tennis Racket: 5.5% sales tax
$63.19
Michael’s bill at a restaurant was $46.32. He wants to leave a 17% tip. What will the total bill be, including tip?
What is $54.19
CVS is having a sale on Luden's Throat Drops for 16% off. if a bag of them costs $4.00 what is the sales price?
What is $3.36?
Rodney want to practice free-throws. He estimates the distance from the free-throw line to the hoop and marks it with chalk. Rodney's estimate was 13.5 feet. The actual distance should be 15 feet. Find the percent of error.
10%
Original amount $16 New amount $28
What is 75%
$84.95 Camera: 8.75% sales tax
$92.38
You and five friends go to Cheesecake factory for your birthday. The total bill comes to $243. You want to tip 20% and the tax is 6%. How much does each person owe?
What is $51.52.
360 is increased by 25%. The result is then decreased by 50%. What is the final number?
$225.00