Question

A scale has a percent error of 7%. The scale reads the mass of a book as 450g. Which statement describes what the actual mass of the book could be

Answer 1

The actual mass of the book is between 481 . 5 g and 418 . 5 g.

Explanation:

The mass of the book on the scale = 450 g

The percentage error in the scale = 7%

So, the actual mass of the book is 450 g ± 7%

Now, 7 % of the mass 450 g =
`(7)/(100)  * 450 = 31.5`

⇒ 7% of 450 g = 31.5 g

Now, the Actual mass of the book = 450 g ± 31.5 g

450 g + 31.5 g = 481 . 5 g

450 g - 31.5 g = 418 . 5 g

Hence the actual mass of the book is between 481 . 5 g and 418 . 5 g.