# ap stats - chapter 2 vocab Flashcards

ogives

cumulative frequency graph

cumulative frequency

adding something up as we go along

relative cumulative frequency

adding something up as we go but turning them into percentages

#/total #

relative

%

normal distribution

a special density curve that is shaped like a bell

normal distribution, aka

normal curve

Mu

characterizes the POSITION of the normal distribution

sigma

characterizes the SPREAD of the normal distribution

total density of a curve =

1

68-95-99.7 rule

remember this

one standard deviation away contains an area of ___?

68%

two standard deviations away contains an area of ___?

95%

three standard deviations away contains an area of

99.7%

standard normal distribution

special type of normal distribution that has a mean of 0 and a standard deviation of 1

z-score

how many standard deviations an observation is away from the mean