Algebra 1 Common Core Student Edition, Grade 8-9

12- 1 Orgonizing Data Using Matrices

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Quick Review

You can use matrices to organize data. To ad d or subtract

m atrices th at are th e sam e size, ad d or subtract the

corresponding elem ents. To m ultiply a m atrix by a scalar,

m ultiply each elem ent by th e scalar.

Ex a m p l e

What is the difference?

3 2 ~ 2 4~ 3 - 2 2-4

-1 5 - 4-3= -1 -4 5-(-3)

2-2 1 0 2- 1 - 2-0

1 -2

-5 8

1 -2

Ex e r c i se s

Find each sum, difference, or product.

-5 1 7 -6

5. —

(^081)
1 CN]
1
0.4 1.5 ~4 3
6. 3.2 + 6.3 -7 .2
1.5 -2.1 1.9 - 0. 5

7. -4.2

3 1.1

3 - 2

• 1 2.9

12- 2 Frequency and Histograms

Quick Review

The freq u e n c y of an interval is th e n u m b e r of data values in

th at interval. A histogram is a graph th at groups d ata into

intervals an d shows the frequency of values in e ach interval.

Ex a m p l e

Below are the prices o f the television m odels sold at an

electronics store. What is a histogram o f the data?

$1399 $1349 $999 $2149 $149 $279 $449 $379 $1379

$799 $3199 $1099 $499 $899 $949 $1799 $1699 $3499

Television Prices

0-999 1000-1999 2000-2999 3000-3999

Price ($)

Ex e r c i se s

Use the data to m ake a histogram.

8. custom ers: 141 128 132 141 152 169 121 133 131

156 142 136 135 144 135 153

9. w orkouttim es(m in):41 29 46 39 37 44 33 51 42 30

Tell w hether each histogram is uniform, sym m etric,

or skewed.

10.

C 01

(^3) O'