Introductory Algebra for College Students (7th Edition)

Published by Pearson
ISBN 10: 0-13417-805-X
ISBN 13: 978-0-13417-805-9

Chapter 2 - Section 2.1 - The Addition Property of Equality - Exercise Set - Page 121: 65


According to the formula, 49% had an average grade of A in 2010. The formula overestimates the percent displayed on the graph by 1%.

Work Step by Step

To find x, the number of years after 1980, subtract 1980 from the given year. Substitute for x and use the addition property of equality to solve the equation for p. $p-0.8x=25$ $p-0.8(2010-1980)=25$ $p-0.8(30)=25$ $p-24=25$ $p-24+24=25+24$ $p=49$ The graph shows the actual percentage was 48%, a difference of 1%. Since the actual number is smaller, the formula overestimates the percentage.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.