1. 4-1 Organizing Data Into Matrices
Objectives : To identify matrices and their elements
To organize into matrices

2. Objectives
Identifying Matrices Organizing Statistical Data

3. (represented with a capital letter)
Vocabulary
A matrix is a rectangular array of numbers written brackets.
3 Columns
Name of the Matrix
(represented with a capital letter)
2 Rows
Dimensions - Matrix A is a 2 x 3 matrix

4. Writing the Dimensions of a Matrix
Write the dimensions of each matrix.
7 –4
The matrix has 2 rows and 2 columns and is therefore a 2  2 matrix. a.
The matrix has 1 row and 3 columns and is therefore a 1  3 matrix. b.
Do Quick Check #1 (all) on Page 168

5. Vocabulary
Each number in a matrix is a matrix element. You can identify a matrix element by its position within the matrix.
Use a lowercase letter with subscripts.
The subscripts represent the element’s row number and column number.

6. Identifying a Matrix Element
Identify each matrix element.
3 –1 –8 5
8 – –5
K =
a. k12
b. k32
c. k23
d. k34
a. K =
k12 is the element in the first row and second column.
3 –1 –8 5
8 – –5
b. K =
k32 is the element in the third row and second column.
3 –1 –8 5
8 – –5
Element k12 is –1.
Element k32 is –4.

7. Do Quick Check #2 (all) on Page 169
Continued
(continued)
3 –1 –8 5
8 – –5
K =
a. k12
b. k32
c. k23
d. k34
c. K =
k23 is the element in the second row and third column.
3 –1 –8 5
8 – –5
d. K =
k34 is the element in the third row and the fourth column.
3 –1 –8 5
8 – –5
Element k23 is 4.
Element k34 is –5.
Do Quick Check #2 (all) on Page 169

8. Real World Example
Three students kept track of the games they won and lost in a chess competition. They showed their results in a chart. Write a
2  3 matrix to show the data.
= Win X = Loss
Ed X X
Jo X
Lew X X X X
Let each row represent the number of wins and losses and each column represent a student.
Wins
Losses
Ed Jo Lew

9. Real World Example Refer to the table. U.S. Passenger Car Imports
And Exports (millions)
a. Write a matrix N to represent the information.
Imports
Exports
Use 2  3 matrix.
Source: U.S. Department of Commerce.
N = Import
Exports
Each column represents a different year.
Each row represents imports and exports.

10. Continued (continued) U.S. Passenger Car Imports
And Exports (millions)
b. Which element represents exports for 2000?
Imports Exports
Source: U.S. Department of Commerce.
Exports are in the second row.
The year 2000 is in the third column.
Element n23 represents the number of exports for 2000.