#### Answer

1991

#### Work Step by Step

Take a look at the y axis. Draw an imaginary line at 20 and check when the graph hits that line

Published by
Pearson

ISBN 10:
0321726391

ISBN 13:
978-0-32172-639-1

1991

Take a look at the y axis. Draw an imaginary line at 20 and check when the graph hits that line

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