Chapter 10 Flashcards
Weighted mean
Like weighted grades
Geometric mean
used to find the average of a set showing growth or decay, values are multiplied together instead of added
Harmonic means
Used for rates of change,
n/ {(1/x1)+(1/x2)…..+(1/xn)}
nominal measurement
Gathers information and labels variables without performing any mathematical operations, useful for mode
ordinal measurement
places values in a certain order, useful for mean.
interval measurement
allows you to find intervals between scores on a test. puts values in order and determines differences between the variables. good for mean median and mode
Random variable
a variable that describes all possible outcomes of a random process
discrete
total number of outcomes is countable
continuous
total number of outcomes is not countable
expected value
the outcome we expect on average
formula: sum of variable x probability (for discrete)
Limit(xF(x)dx (for continuous)
quartile
a group of values and or means that divide a set into quarters or four groups
Interquartile range
a value that is the difference between the upper quartile value and the lower quartile value
Formula for expected value for discrete probability distribution.
E(x) = NsumK=0 (XsubK * P(Xsubk)