A student lost part of his lab notebook and didn't know what the original measure should have been. He knows that he calculated a 35.5% error and his experimental measurement was 15.6 cm. What are the two possible values for the actual measurement?

21.1cm or 10.1cm

Explanation:

Since the percent error is 35.5% and the experimental measurement was 15.6cm, the two possible values for the actual measurement are 15.6 plus 35.5% of 15.6 or 15.6 minus 35.5% of 15.6.

This is this:

15.6 + (0.355 x 15.6)

= 15.6 + 5.54

= 21.1cm

Or this:

15.6 - (0.355 x 15.6)

= 15.6 - 5.54

= 10.1cm