Section 7.3 Section 7.3 (p. 259)(p. 259)

VocabularyVocabulary

List the 3 measures of Central List the 3 measures of Central TendencyTendency

A) Mean ( ): _________________________A) Mean ( ): _________________________

B) Median: ____________________________B) Median: ____________________________

C) Mode: _____________________________C) Mode: _____________________________

X

VocabularyVocabulary

1) Statistics: ____________________1) Statistics: ____________________

________________________________________________________

2) Measure of Dispersion: _________2) Measure of Dispersion: _________

________________________________________________________

3) Range: ______________________3) Range: ______________________

VocabularyVocabulary

4) Standard Deviation4) Standard Deviation

: _______: _______

: ________________________: ________________________

n : ___________n : ___________

2 2 2

1 2 ... nx X x X x X

n

EXAMPLE 1 Find measures of central tendency

TEST SCORES

TEST SCORES: 42, 72, 81, 95, 98, 58, 77, 75, 52

83, 97, 45, 89, 93, 57, 82, 97, 75

Mean: ________ Median: ________ Mode: ________

42, 45, 52, 57, 58, 72, 75, 75, 77, 81, 82, 83, 89, 93, 95, 97, 97, 98

EXAMPLE 2 Find Range

TEST SCORES

TEST SCORES: 88, 25, 78, 95, 67, 54

Range: ________

EXAMPLE 2 Find Standard Deviation

TEST SCORES

TEST SCORES: 88, 25, 78, 95, 67, 54

( 25 – 68) 2 = 1849

( 54 – 68) 2 = 196

( 67 – 68) 2 = 1

( 78 – 68) 2 = 100

( 88 – 68) 2 = 400

( 95 – 68)2 = 729

Standard Deviation: ________

2 2 2

1 2 ... nx X x X x X

n

Writing Data Sets as a Writing Data Sets as a LIST OF VALUESLIST OF VALUES

The data set gives the scores for the University of Georgia football team over a 12 game season.

49 21 28 10 7 24 21 12 17 35 42 14

Writing Data Sets as a Writing Data Sets as a FREQUENCY TABLEFREQUENCY TABLE

iX iF = frequency

2 3

3 2

4 5

5 1

FINDING STANDARD DEVIATION W/ CALCULATORS

GRAPHING

STAT

1) EDIT

ENTER #’s in L1

STAT

Rt Arrow – CALC

1)1-VAR STAT

2)ENTER…ENTER

FINDING STANDARD DEVIATION W/ CALCULATORS

YELLOW BLUE

data 2nd DATA (STAT)

ENTER #’s in L1 - 1-VAR

2nd data (stat) DATA

Hit ENTER 4 times - Enter #’s (use arrow)

- 1-Var Stats - FRQ = 1 (frequency)

- DATA – L1 STATVAR

- FRQ – ONE - use arrow key to scroll

- CALC