Beginning Algebra, 11th Edition

76.The table shows the number of U.S. students who

studied abroad (in thousands) for several aca-

demic years.

186 CHAPTER 3 Linear Equations and Inequalities in Two Variables; Functions

(a)Complete the table of values for this linear equation.

(b)Write the data from the table of values as ordered pairs.

(c)Make a scatter diagram of the data. Describe the pattern indicated by the data.

y

x

260

240

220

200

180

160

(^020012003)
Year
2005
U.S. STUDENTS
STUDYING ABROAD
Number of Students
(in thousands)
Number of Students
Academic Year (in thousands)
2001 161
2002 175
2003 191
2004 206
2005 224
2006 242
Source:Institute of International Education.
(a)Write the data from the table as ordered pairs where xrepresents the year and
yrepresents the number of U.S. students (in thousands) studying abroad.
(b)What does the ordered pair mean in the context of this problem?
(c)Make a scatter diagram of the data, using the ordered pairs from part (a) and the given
grid.
(d)Describe the pattern indicated by the points on the scatter diagram. What was the
trend in the number of U.S. students studying abroad during these years?
77.The maximum benefit for the heart from exercising occurs if the
heart rate is in the target heart rate zone. The lower limit of this
target zone can be approximated by the linear equation
where xrepresents age and yrepresents heartbeats per minute.
(Source: The Gazette.)
(a)Complete the table of values for this linear equation.
(b)Write the data from the table of values as ordered pairs.
(c)Make a scatter diagram of the data. Do the points lie in an approximately linear
pattern?
78.(SeeExercise 77.) The upper limit of the target heart rate zone can be approximated by
the linear equation
where xrepresents age and yrepresents heartbeats per minute. (Source: The Gazette.)
y=-0.85x+187,
y=-0.65x+143,

1 2006, 2422

1 x, y 2 ,

Heartbeats

Age (per minute)

20

40

60

80

Heartbeats

Age (per minute)

20

40

60

80

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