6.1 Review
By: Breezy Berteau
Empirical Rule
 Normal Curve
 Control Chart

Empirical Rule
 68% of data will lie within 1 standard deviation on each side of the mean
 95% of data will lie within 2 standard deviations on each side of the mean
 99.7% of the data will lie within 3 standard deviations on each side of the mean
Normal Curve
 Curve is bell shaped, with the highest point over the mean µ
 Curve is symmetrical about a vertical line through µ
 The curve approaches the horizontal axis but never touches or crosses it
 The inflection/transition points between cupping upward and downward occur above µ + 0 and µ  0
 The area under the entire curve is 1
Control Chart
 Find the mean µ and standard deviation 0 of the x distribution by
 Using past data from a period during which the process was in control or
 Using a specified "target" values for µ and 0
 Create a graph where the vertical axis represents x values and the horizontal axis represents time
 Draw a horizontal like at height µ, dashed controllimit lines at µ + 2"0" and µ + 3"0"
 Plot the variable x on the graph in time sequence order. Use line segments to connect the points
Z Score and Raw Score
Z = (measurement  mean of distribution)/ standard deviation of distribution
X = (number of standard deviations)(standard deviation of the distribution) + mean of the distribution