160 likes | 266 Views
Warm-Up. Find the mean of the following calorie intake an individual has in one day. 1588, 3190, 2150, 2008, 1854, 1650, 2140. Notes 2.4 (Part 1). Measures of Variation. Range.
E N D
Warm-Up Find the mean of the following calorie intake an individual has in one day. 1588, 3190, 2150, 2008, 1854, 1650, 2140
Notes 2.4 (Part 1) Measures of Variation
Range • Range: is the difference from the maximum and minimum entry of a data set. It allows you to know how the data entries are dispersed. Ex 1 45 8 74 96 74 15 14 101 80 45 20 4 8
Range • Range: is the difference from the maximum and minimum entry of a data set. It allows you to know how the data entries are dispersed. Ex 1 45 8 74 96 74 15 14 101 80 45 20 4 8 Range = 101 - 4 = 97
Deviation Deviation: is the difference of a data entry to the mean of the data set. • 5 6 10 14 16 24 35 Mean = 114 = 14.25 8
5 6 10 14 16 24 35 Mean = µ = 14.25 µ = mu Values Deviations X x - µ 4 5 6 10 14 16 24 35
5 6 10 14 16 24 35 Mean = µ = 14.25 µ = mu Values Deviations X x - µ 4 -10.25 5 6 10 14 16 24 35
5 6 10 14 16 24 35 Mean = µ = 14.25 µ = mu Values Deviations X x - µ 4 -10.25 5 -9.25 6 -8.25 10 -4.25 14 -.25 16 1.75 24 9.75 35 20.75 ∑x=114 ∑ x - µ = 0
1) x - µ (deviations column) should always add up to zero 2) Deviation squared will always be positive since you are squaring the number Values Deviation Deviation Squared X x - µ (x - µ)² 4 -10.25 105.06 5 -9.25 6 -8.25 10 -4.25 14 -.25 16 1.75 24 9.75 35 20.75 ∑x=114 ∑ x - µ = 0
1) x - µ (deviations column) should always add up to zero 2) Deviation squared will always be positive since you are squaring the number Values Deviation Deviation Squared X x - µ (x - µ)² 4 -10.25 105.06 5 -9.25 85.56 6 -8.25 68.06 10 -4.25 18.06 14 -.25 0.06 16 1.75 3.06 24 9.75 95.06 35 20.75 430.56 ∑x=114 ∑ x - µ = 0 ∑ (x - µ)²= 805.48
Warm-Up • 13 5 11 4 12 10 6 8 Find the values, deviation and deviations squared columns 1) Find the mean first 2) Values Deviation Deviation Squared X x - µ (x - µ)²
Values Deviation Deviation Squared X x - µ (x - µ)² 1 13 5 11 4 12 10 6 8
Mean = 70 = 7.7789 Values Deviation Deviation Squared X x - µ (x - µ)² 1 -6.778 45.941 13 5.222 27.269 5 -2.778 7.717 11 3.222 10.381 4 -3.778 14.273 12 4.222 17.825 10 2.222 4.937 6 -1.778 3.161 8 0.222 0.049 ∑ (x - µ)² = 131.553
Sample Variance Sample variance = σ² = ∑ (x - µ)² n - 1
Sample Standard Deviation Sample standard = σ = √∑ (x - µ)² deviation n - 1