Statistics Chapter 13

What is Empirical Rule for a Normal Distribution?

-"68%-95%-99.7% Rule"

If X ~ N(µ,σ) then Z ~ N(__,__) (______)

-(0,1) the Standard Normal Distribution

What is Standard Score? ---> -(or _______) -is the number of ______ above or below the _______ -Formula?

-(or z-score) -is the number of deviations above or below the mean at which an observation (x) is located -(Observation(x)- Mean)/(Standard Deviation)

If an observation x is >, <, or = to the mean? (z-score is _____, ____, _____)

-> Mean,, then its z-score will be positive -< mean, then its z-score will be negative -= mean, then its z-score will equal zero

Know what the "68-95-99.7" Rule look like. AND µ = ___ & σ = ___

-Slide 3 -µ = 0 & σ = 1

What is the usefulness of Standard Scores? --> -We can _______ the values of different _________ data sets

-compare -normally distributed

100%--> -of the values lie somewhere in the _________ (_____% > or < Mean)

-of the values lie somewhere in the normal distribution (50% < mean & 50% > mean)

68% --> -of the values lie within _____ standard deviation on either side of the mean

-one

The ____ of the distribution does not change; the ____(__) and _____(___) do

-shape, (µ )center, (σ) spread

µz = ____

0

σ z= ____

1

99.7% --> -of the values lie within ______ standard deviations on either side of the mean

3

95% --> -of the values lie within ______ standard deviations on either side of the mean

two