PLEASE HELP, 40 POINTS!!!!!!!!!!!!!!!!!!!
Remember that in Cynthia's physics class, she must turn in four lab reports. For each report, she earns extra credit if her percent error is less than 5%.
For her second lab report, she calculated the height of a building four times. She got the following four heights.

6.8 m
7.5 m
8.1 m
7.8 m
The true height of the building is 7 m.

What was Cynthia's percent error?

Remember: Take the average of the three measurements before calculating the percent error.