1. Definitions

2. Definitions Mode - the value that occurs most frequently Find the Mode
5, 3, 7, 2, 4, 4, 2, 4, 8, 3, 4, 3, 4

3. Definitions Median - The central value of an ordered distribution
Order the data from smallest to largest
For a distribution with an odd number of data values, Median = Middle data value
For a distribution with an even number of data values, Median= (Sum of middle values)/2

4. Definitions Find the Median 18, 19, 19, 27, 28 Answer: 19
18, 19, 19, 27, 28, 35
Answer: (19+27)/2 = 23
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5. For an ordered data set of size n,
Definitions
For an ordered data set of size n,
Position of the middle value = (n+1)/2
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6. 12 13 14 15 16 17 18 19 20

7. Mean =(Sum of all entries)/Number of entries
Definitions
Mean =(Sum of all entries)/Number of entries
Find the mean: 58, 67, 60, 84, 93, 98, 100
Answer = ( )/7
= 80
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8. Definitions Summation Symbol Σ Σx= Sum of all given x values
X - the mean of a sample distribution (Read “x bar”)
X=Σx/n
Where n = number of data values in the sample

9. Definitions - (pronounced “mew”)
Used to represent the mean when the data comprise the entire population
= Σx/N
Where N = number of data values in the population
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10. Definitions
Resistant measure - one that is not influenced by extremely high or low data values
Generally referred as a scale (more resistant, less resistant)
Mode is a resistant measure
Mean is not a resistant measure
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11. Definitions
Trimmed Mean - The mean of the data values left after “trimming” a specified percentage of the smallest and largest data values from the data set.
More resistant
Usually 5% is used
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12. Definitions Trimmed Mean - How to Calculate
Order data from smallest to largest
Delete established percentage of data from the top and bottom. (Round percentages)
Compute the mean of the remaining percentage
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13. Definitions
Trimmed Mean - 14 20 23 25 30 35 40 42 50 80
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14. Definitions Weighted average - Weighted Average = Σxw/Σw
Where x is a data value and w is the weight assigned to that data value. The sum is taken over all data values.
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15. Example
Assume Tests are worth 50% of your grade, Quizzes 20 %, and daily work 30%.
If you received an average of 95% in tests, 88% in quizzes, and 100% in daily work, what is your final grade?

16. Pg. 89
1, 2, 4, 12, 13, 18, 20