Basic Mathematics for College Students

Recall that the arithmetic mean,or average,of several numbers is a value around which
the numbers are grouped. We use addition and division to find the mean (average).

4.4 Dividing Decimals 367

Now that the divisor is a whole number, we can perform the division.

StateThere are 40 slices in one loaf of French bread.

CheckThe multiplication below verifies that 40 slices, each 0.625-inch thick,
makes a 25-inch-long loaf. The result checks.

The thickness of one slice of bread (in inches)

The number of slices in one loaf

The length of one loaf of bread (in inches)

0.625

 40

0000

25000

25.000

40

(^625)  25000
 2500
00
 0
0
EXAMPLE (^12) Comparison Shopping An online shopping website,
Shopping.com, listed the four best prices for an automobile GPS receiver as shown
below. What is the mean (average) price of the GPS?
Self Check 12
U.S. NATIONAL PARKSUse the
following data to determine the
average number of visitors per
year to the national parks for
the years 2004 through 2008.
(Source: National Park Service)
Now TryProblem 103
200 W Car GPS Receiver
Ebay
Amazon
Target
Overstock
Shopping.com
$169.99
$182.65
$194.84
$204.48
Year Visitors (millions)
2008 2.749
2007 2.756
2006 2.726
2005 2.735
StrategyWe will add 169.99, 182.65, 194.84, and 204.48 and divide the sum by 4. 2004 2.769
WHYTo find the mean (average) of a set of values, we divide the sum of the values
by the number of values.
Solution
In the numerator, do the addition.
187.99 Do the indicated division.



751.96

4

Since there are 4 prices, divide the

Mean sum by 4.

169.99182.65194.84204.48

4

187.99

4 751.96

 4

35

 32

31

 28

39

 36

36

 36

0

1

2

6

2

9

2

.9

2

9

182.65

194.84

204.48

751.96

The mean (average) price of the GPS receiver is $187.99.