7th Grade Math

Extra Practice begins on page EP2.

Lesson 2D Proportions and Equations 343

= Step-by-Step Solutions begin on page R1.

Extra Practice begins on page EP2.

Use the determine reasonable answers

strategy to solve Exercises 3–6.

3. TIPS Brett decides to leave a 20% tip on a
   restaurant bill of $17.50. How much should
   he tip the restaurant server?

$17.50

tip

4. SCHOOL Of 423 students, 57.6% live within
   5 miles of the school. What is a reasonable
   estimate for the number of students living
   within 5 miles of the school? Explain.


5. EXERCISE A survey showed that 61% of
   middle school students do some kind of
   physical activity every day. If there are
   828 middle school students in your school,
   would the number of students who
   exercise be about 300, 400, or 500? Explain.


6. TRAVEL A travel agency surveyed 140
   families about their favorite vacation spots.
   Is 60, 70, or 80 families a reasonable
   estimate for the number of families that
   did not choose Hawaii?



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$BMJGPSOJB



'MPSJEB

Favorite Vacation Spots

Use any strategy to solve Exercises 7–13.

7. COINS Gavin has 10 coins that total $0.83.
   What are the coins?
   8. BAKING Refer to the graph. A pie is set
   out to cool. Is it reasonable to estimate
   that the pie will be 90°F after ten minutes
   of cooling? Explain.

1234

Temperature (°F)

Time (min)

145

141

137

133

Pie Temperature

150

145

140

135

130

125

0

99 SHOPPING Deshawn wants to buy a shirt

that has a regular price of $41 but is now

on sale for 25% off the original price. Is

$25, $30, or $35 the best estimate for the

cost of the shirt?

10. BOWLING In bowling, you get a spare
    when you knock down the ten pins in
    two throws. How many possible ways
    are there to get a spare?


11. SAVING Aliayah saves $11 each month for
    her class trip. What is a reasonable estimate
    for the amount of money she will have
    saved after a year: about $100, $120, or
    $160? Explain.


12. FUNDRAISER During a popcorn sale for
    a fundraiser, the soccer team gets to keep
    25% of the sales. One box of popcorn
    sells for $1.50 and the team has sold
    510 boxes so far. Has the team raised a
    total of $175? Explain.


13. MEASUREMENT How many square yards of
    carpet are needed to carpet the two rooms
    described below? Explain.

Room Dimensions

Living room 15 ft by 18 ft

TV room 18 ft by 20 ft

• Determine reasonable answers.


• Guess, check, and revise.


• Look for a pattern.


• Choose an operation.

342_343_C06_PSI_895130.indd 343 12/30/09 4:06 PM