VARIANCE
Variance is based on the deviation about the mean.
For a population, the deviation about the mean for the ith observation is xi
For a sample, the deviation about the mean for the ith observation is xi
The further the deviation from the mean, t
THEMODE
The mode of a variable is the most frequent observation of the variable that occurs in the
data set.
ComputingtheMode
Tally the number of observations that occur for each data value. The data value that
occurs most often is the mode.
No mode- if
Mutat Re
TestSD' [ Statistics
Directions: Work on these sheets.
Part 1: Multiple Choice. Circle the letter corresponding to the best anmer. I
1. Which of the following is CORRECT?
(a) We do not need to randomize if our sample size is sufciently l
Thewordaverage
The average miles per gallon of gasoline of the 2005 Chevrolet Camaro in city driving is
19 miles.
According to the U.S. Census Bureau, the average household income in 2003 was $43,
527
The average American woman is 54 tall and weighs 142