610 Chapter 7 Graphs and Statistics
WHYTo find the mean (average) of a set of values, we divide the sum of the values
by the number of values. In this case, there are 6 days of sales (Monday through
Saturday).
Solution
Since there are 6 days of sales, divide the sum by 6.In the numerator, do the addition.Do the division.
The mean of the week’s daily sales in the women’s department is $2,406.Using Your CALCULATOR Finding the Mean
Most scientific calculators do statistical calculations and can easily find the
mean of a set of numbers. To use a scientific calculator in statistical mode to
find the mean in Example 1, try these keystrokes:- Set the calculator to statistical mode.
- Reset the calculator to clear the statistical registers.
- Enter each number, followed by the key instead of the key.
That is, enter 3,135, press , enter 2,310, press , and so on. - When all data are entered, find the mean by pressing the key. You
may need to press first. The mean is 2,406.
Because keystrokes vary among calculator brands, you might have to check
the owner’s manual if these instructions don’t work.
2 ndx_
g gg $2,406
$14,436
6
Mean$3,135$2,310$3,206$2,115$1,570$2,100
6
Total Daily Sales Per Department—Clothes Shoppe
Day Men’s Women’s Children’s
department department department
Monday $2,315 $3,135 $1,110
Tuesday 2,020 2,310 890
Wednesday 1,100 3,206 1,020
Thursday 2,000 2,115 880
Friday 955 1,570 1,010
Saturday 850 2,100 1,0002406(^6) 14,436
12
24
24
03
0
36
36
0
3
1
,1
1
3
1
5
2,310
3,206
2,115
1,570
2,100
14,436
EXAMPLE (^2) Driving In the month of January, a
trucker drove a total of 4,805 miles. On the average, how many
miles did he drive per day?
StrategyWe will divide 4,805 by 31 (the number of days in
the month of January).
Self Check 2
TRUCKINGIf a trucker drove
3,360 miles in February, how
many miles did he drive per day,
on average? (Assume it is not
a leap year.)
Now TryProblem 43
SSMTWT F
142 3
5116 7 8 910
12 18 1314151617
19 25 2021222324
26 31 27282930
January
iStockphoto.com/fotoIE