Question

Ernesto guesses there are 69 marbles in a jar, but there are actually 60.

What is the percent error in Ernesto's guess?

Answer 1

15%

Explanation:

Since the problem is to find how much 69 is as a percent if 60 is 100%, we can use a rule of three, simple, direct proportion to do it:

60 = 100%

68 = x

x = 69x100/60

x = 115

That means 69 is 115% of 60, which means that the error is of:

115 - 100 = 15%

Hope this helps, have a great day! :D