117.In 1998, undergraduate college students had an average (mean) credit card balance of
$1879. The average balance increased $869 by 2000, then dropped $579 by 2004, and
then increased $1004 by 2008. What was the average credit card balance of undergrad-
uate college students in 2008? (Source:Sallie Mae.)
118.Among entertainment expenditures, the average annual spending per U.S. household on
fees and admissions was $526 in 2001. This amount decreased $32 by 2003 and then in-
creased $112 by 2006. What was the average household expenditure for fees and ad-
missions in 2006? (Source:U.S. Bureau of Labor Statistics.)
119.Nadine Blackwood enjoys playing Triominoes every Wednesday night. Last Wednesday,
on four successive turns, her scores were , 28, and 13. What was her final score
for the four turns?
120.Bruce Buit also enjoys playing Triominoes. On five successive turns, his scores were
- 13,15, -12,24, and 14. What was his total score for the five turns?
- 19 - 5,
SECTION 1.5 Adding and Subtracting Real Numbers 47
123.Linda Des Jardines owes $870.00 on her MasterCard account. She returns two items cost-
ing $35.90 and $150.00 and receives credit for these on the account. Next, she makes a
purchase of $82.50 and then two more purchases of $10.00 each. She makes a payment
of $500.00. She then incurs a finance charge of $37.23. How much does she still owe?
124.Marcial Echenique owes $679.00 on his Visa account. He returns three items costing
$36.89, $29.40, and $113.55 and receives credit for these on the account. Next, he makes
purchases of $135.78 and $412.88 and two purchases of $20.00 each. He makes a pay-
ment of $400. He then incurs a finance charge of $24.57. How much does he still owe?
The bar graph shows federal budget outlays for the U.S. Department of Homeland Security
for the years 2005 through 2008. In Exercises 125–128, use a signed number to represent the
change in outlay for each period. See Example 11.
121.In August, Susan Goodman began with
a checking account balance of $904.89.
Her checks and deposits for August are
as follows:
Assuming no other transactions, what
was her account balance at the end of
August?122.In September, Jeffery Cooper began
with a checking account balance of
$904.89. His checks and deposits for
September are as follows:Assuming no other transactions, what
was his account balance at the end of
September?Checks Deposits
$35.84 $85.00
$26.14 $120.76
$3.12Checks Deposits
$41.29 $80.59
$13.66 $276.13
$84.40YearFederal Budget Outlays for Homeland SecuritySource: U.S. Department of Management and Budget.
*Estimated
030405060702005 2006 2007 2008*69.138.7 39.2 42.3Billions of Dollars125.2005 to 2006 126.2006 to 2007
127.2007 to 2008 128.2005 to 2008