Question

A student measures the weight of one bottle cap as 5.03 grams, so he calculates that the weight of 100

bottle caps will be 503 grams. The actual weight of 100 bottle caps is 495 grams. What is the student's percent error?percent error?

Answer 1

2489.85 or 98.4095% is the answer Method 1: Diagonal multiplication to calculate "What percent of 503 is 495"

For 503, our answer will be 495
For 100, our answer will be x
503*x = 100*495 (In Step 1 and 2 see colored text; Diagonal multiplications will always be equal)
x = 100*495/503 = 49500/503 = 98.4095
98.4095% of 503 is 495

Method 2: Same side division to calculate "What percent of 503 is 495"

For 503, our answer will be 495
For 100, our answer will be x
495/x = 503/100 (In Step 1 and 2, see colored text; Same side divisions will always be equal)
503/100 = 495/x or x/495 = 100/503
x = 495*100/503 = 49500/503 = 98.4095
98.4095% of 503 is 495