Page 330 - Basic College Mathematics with Early Integers

S E C T I O N 4.3 I MULTIPLYING DECIMALS AND CIRCUMFERENCE OF A CIRCLE 307

Objectives Mixed Practice Multiply. See Examples 1 through 10.

29. 0.123 * 0.4 30. 0.216 * 0.3 31. (147.9)(100) 32. (345.2)(100)

33. 8.6 * 0.15 34. 0.42 * 5.7 35. (937.62)(-0.01) 36. (-0.001)(562.01)

37. 562.3 * 0.001 38. 993.5 * 0.001 39. 6.32 40. 9.21
* 5.7 * 3.8

Write each number in standard notation. See Example 11.

41. The cost of the Hubble Space Telescope at launch was 42. About 44.8 million American households own at least
$1.5 billion. (Source: NASA) one dog. (Source: American Pet Products
Manufacturers Association)
43. The Blue Streak is the oldest roller coaster at Cedar 44. In 2008, the restaurant industry had projected sales
Point, an amusement park in Sandusky, Ohio. Since of $558.3 billion. (Source: National Restaurant
1964, it has given more than 49.8 million rides. Association)
(Source: Cedar Fair, L.P.)

Objective Evaluate each expression for x = 3, y =-0.2, and z = 5.7. See Example 12.

45. xy 46. yz 47. xz - y 48. -5y + z

Objective Find the circumference of each circle.Then use the approximation 3.14 for and approximate eachp
circumference. See Example 13.

49. 50. 51. 52.

10 centimeters 22 inches 9.1 yards

5.9 kilometers

Objectives Mixed Practice Solve. For Exercises 53 and 54, the solutions have been started for you.
See Examples 13 and 14. For circumference applications find the exact circumference and then use 3.14 for top
approximate the circumference.

53. An electrician for Central Power and Light worked 54. An assembly line worker worked 20 hours last week.
40 hours last week. Calculate his pay before taxes for Her hourly rate is $19.52 per hour. Calculate her pay
last week if his hourly wage is $17.88. before taxes.
Start the solution: Start the solution:
1. UNDERSTAND the problem. Reread it as many 1. UNDERSTAND the problem. Reread it as many
times as needed. times as needed.
2. TRANSLATE into an equation. (Fill in the blanks.) 2. TRANSLATE into an equation. (Fill in the blanks.)
pay before is hourly times hours pay before is hourly times hours
taxes wage worked taxes rate worked

T T T T T T T T T T
pay before pay before
= _____ * _____ = _____ * _____
taxes taxes
Finish with: Finish with:
3. SOLVE and 4. INTERPRET. 3. SOLVE and 4. INTERPRET.