Week 3 Quiz Review for Math 221

B. Heard(These may not be copied, reproduced, or posted in an online classroom without my

permission. Students may download one copy for personal use.)

Week 3 Quiz Review

• Data Collection

– Sampling

– Census

– Experiments

– Simulations

– Etc.

Week 3 Quiz Review

• Descriptive & Inferential Statistics

– Know the difference

– Descriptive - This is a set of methods to describe data that we have collected.

– Inferential - This is a set of methods used to make a generalization, estimate, prediction or decision.

Week 3 Quiz Review

• Know the difference between Qualitative and Quantitative Data

Week 3 Quiz Review

• Types of Sampling

– Random

– Stratified

– Cluster

– Systematic

– Convenience

Week 3 Quiz Review

• Populations and Samples

– Parameters and Statistics

Week 3 Quiz Review

• Standard Deviation and Variance

– How to calculate and mathematical relationship.

– Variance is the Standard Deviation squared.

– Standard Deviation is the square root of the Variance.

Week 3 Quiz Review

• Be able to get a regression equation.

• Example

– Data (4, 30), (4,35), (5,36), (6,42), (8,48)

Week 3 Quiz Review

• Be able to get a regression equation.

• Example

– Data (4, 30), (4,35), (5,36), (6,42), (8,48)

Week 3 Quiz Review

• Be able to get a regression equation.

• Example

– Data (4, 30), (4,35), (5,36), (6,42), (8,48)

Week 3 Quiz Review

• Be able to get a regression equation.

• Example

– Data (4, 30), (4,35), (5,36), (6,42), (8,48)

This would be written as y = 3.982x + 16.70

Week 3 Quiz Review

• Use a multiple regression equation.

• Plug and Chug

• y = -6.5 +12a + 5.1 b where a is test score and b is a competency score. y predicts the person’s score on a job test.

• Predict a job test score for a person who made a 50 on the test and got a 7 as a competency score.

• y = -6.5 +12(50) + 5.1 (7)

• Y = 629.2

Week 3 Quiz Review

• Correlation Coefficients, also noted as “r”• Range from -1 to +1

• .75 to 1 is strong

• .5 to .75 is moderate

• .25 to .5 is weak

• 0 to .25 is very weak (closer to zero, almost none)

• + would be positive correlation, - would be negative correlation

• For example, -0.58 would be moderate negative correlation

Week 3 Quiz Review

• Be able to create a stem and leaf plot and determine descriptive statistics.• Mean

• Median

• Mode

• Range

• Variance

• Standard Deviation

• Use Minitab!

Week 3 Quiz Review

• Identify Class Width• Identify Midpoint of certain classes• Identify class boundaries• Give the relative frequency• Fishing Tournament Data below is an example

Number of Fish Frequency

0-7 9

8-15 15

16-23 12

24-31 3

Week 3 Quiz Review

• Class Width is 8

Number of Fish Frequency

0-7 9

8-15 15

16-23 12

24-31 3

8-0 = 8, or you could havesaid 15 – 7 = 8, or counton your fingers, 0,1,2,3,4,5,6,7(There are eight numbers,don’t let it fool you)

Week 3 Quiz Review

• Midpoint of second class is 11.5

Number of Fish Frequency

0-7 9

8-15 15

16-23 12

24-31 3

8+15 = 23 divided by 2 gives you 11.5

Week 3 Quiz Review

• What are the class boundaries of the third class? 15.5 and 23.5

Number of Fish Frequency

0-7 9

8-15 15

16-23 12

24-31 3Subtract .5 from the lower to get 15.5 and add .5 to the upper to get 23.5

Week 3 Quiz Review

• Give the relative frequency of all classes

Number of Fish Frequency Relative Frequency

0-7 9 9/39

8-15 15 15/39

16-23 12 12/39

24-31 3 3/39

Total of 39

Week 3 Quiz Review

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