Stats Ch 3

most extreme observations that still lie within the lower and upper limits

adjacent values

at least 89% of the observation lie within 3 standard deviations to either side of the mean

chebycher's rule

____ is a resistant measure and is preferred when median is the measure of center

interquartile range

The ____ is typically pulled away from the visual center toward the direction of skewness by unusually large (or unusually small) values

mean

the most commonly used measure of central tendency is ____

mean

these measures of central tendency ____ and ____ apply only to quantitative data

mean median

what are the measures of central tendency

mean median mode

Descriptive measures that indicate where the center, or most "typical value," of a data set lies are called _______

measures of central tendency

____ of a data set is the number that divides the bottom 50% of data from the top 50% of the data

median

The _______ are resistant measures of center because they are not sensitive to a few outliers

median and mode

five number summary includes

min Q1 Q2 Q3 max

this measure of central tendency ____ is for qualitative or quantitative data

mode

observations that fall outside the data pattern

outliers

a descriptive measure for a population

parameter

unlike mean and standard deviation _____ are resistant

percentiles

IQR=

Q3-Q1

median equation when data is in increasing order

X(n+1)/2

deciles

10 equal parts

percentiles

100 equal parts

quartiles

4 equal parts

quintiles

5 equal parts

within a bell shaped distribution we can apply empirical rule saying rougly _____ of observations lie within 3 standard deviations to either side of the mean

99.7%

symmetric mean ____ median left skewed mean_____ median right skewed mean ____ median

= < >

lower limit=

Q1-(1.5*IQR)

upper limit=

Q3+(1.5*IQR)

N=

population size

observations that lie below the lower limit or above the upper limit

potential outliers

median of the part of the data that lies at or below the median of the entire data

quartile 1

median of the entire data set

quartile 2

median of the part of data that lies at or above the median of the entire data

quartile 3

n=

sample size

a descriptive measure for a sample

statistic

almost all the observations in any data set lie within three standard deviations to either side of the mean

three standard deviations rule

a _____ can improve the resistance of the mean by removing a percentage of the smallest and largest observations before computing the mean

trimmed mean

The _____ is the number of standard deviations that the value of x is from the mean

z-score

standardized variable

z=x-mu/sigma

A standardized variable always has mean ____ and standard deviation ____

zero one