CK-12 Basic Probability and Statistics - A Short Course

http://www.ck12.org Chapter 5. The Shape, Center and Spread of a Normal Distribution - Basic

TABLE5.6:(continued)

Datax Mean(x ̄) (Data –Mean)(x−x ̄) (Data - Mean)^2 (x−x ̄)^2

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

9.5 9.5 0 0

10 9.5 0.5 0.25

10 9.5 0.5 0.25

10 9.5 0.5 0.25

11 9.5 1.5 2.25

11 9.5 1.5 2.25

190 10.5

x= 9. 5

σ= 0. 72

10. (a) 68%

(b) 13.5%

(c) 99.7%

(b) 47.5%

(d) 48.85%

Vocabulary

Normal Distribution

A symmetric bell-shaped curve with tails that extend infinitely in both directions from the mean of a data set.

Standard Deviation

A measure of spread of the data equal to the square root of the sum of the squared variances divided by the

number of data.

Variance

A measure of spread of the data equal to the mean of the squared variation of each data value from the mean.

68-95-99.7 Rule

The percentages that apply to how the standard deviation of the data spreads out from the mean of a set of

data.