Basic Mathematics for College Students

Chapter 6 Summary and Review 577







Method 2:To find the unknown amount write and then solve a percent

proportion.

is of

This is the proportion

to solve.

Simplify the ratio:.

Find the cross products and set them equal.

On the right side, do the multiplication.

To isolate xon the left side, divide both sides of the

equation by 50. Then remove the common factor of

50 from the numerator and denominator.

On the right side, divide 4,485 by 50. The answer is

in millions.

In April of 2009, there were approximately 89.7 million male users of

Facebook worldwide.

x89.7

x 50

1

50

1



4,485

50

x 50 4,485

x 50  195  23

46

100 

2

1

 23

21  50 

23

(^50)
x
195



23

50

x

195



46

100

amount percent base

What number 46% 195 million?

31. a. Identify the amount, the base, and the percent in
    the statement “15 is 33 13 %of 45.”

REVIEW EXERCISES

33. Translate each percent sentence into a percent
    equation.Do not solve.
    a. What number is 32% of 96?
    b. 64 is what percent of 135?
    c. 9 is 47.2% of what number?


34. Translate each percent sentence into a percent
    proportion.Do not solve.
    a. What number is 32% of 96?
    b. 64 is what percent of 135?
    c. 9 is 47.2% of what number?
    Translate to a percent equation or percent proportion and then
    solve to find the unknown number.


35. What number is 40% of 500?


36. 16% of what number is 20?


37. 1.4 is what percent of 80?


38. of 3,150 is what number?


39. Find 220% of 55.


40. What is 0.05% of 60,000?

66 23 %

b. Fill in the blanks to complete the percent

equation (formula):

percent 

or

Part whole

32. When computing with percents, we must change the
    percent to a decimal or a fraction. Change each
    percent to a decimal.
    a. 13% b. 7.1%
    c. 195% d.
    When computing with percents, we must change the
    percent to a decimal or a fraction. Change each
    percent to a fraction.
    e.
    f.
    g. 16 23 %

66 23 %

33 13 %

1

4 %