Standard Normal Calculations Section 2 2 zscore Standardized

Standard Normal Calculations Section 2. 2

z-score Standardized value Tells how many standard deviations the original observation falls away from the mean, and in which direction

Standard Normal Distribution Normal distribution N(0, 1)

The Standard Normal Table Known as Table A The table entry for each z score is the area under the curve to the left of z

Finding Normal Proportions Draw a picture of the distribution and shade the area of interest under the curve Standardize your observed variable x to a zscore Find the required area under the curve using Table A and the fact that the total area under the curve is equal to 1 Write your conclusion in the context of the problem

Practice Problems pg. 95 #2. 19 -2. 20 pg. 103 #2. 21 -2. 25

Two ways to assess normality Interpreting graphs Constructing a Normal probability plot

Constructing a Normal Probability Plot Use STAT to get your one-variable statistics ◦ You can compare means and medians to look at the symmetry of the distribution Go to STAT PLOT and choose the very last graph ZOOM STAT If the data distribution is close to a normal distribution, then the plotted points will lie close to a straight line

Practice Problems pg. 108 #2. 26 pg. 113 #2. 38 -2. 54