Unit 1.2 & 1.3 Vocab Quiz AP Stat

Dotplot

shows each data value as a dot above its location on a number line

Roughly Symmetric

if the right side of the graph (containing the half of observations with the largest values) is approximately a mirror image of the left side

Skewed to the right

if the right side of the graph is much longer than the left side

Skewed to the left 

if the left side of the graph is much longer than the right side

Stemplot

shows each data value seperated into two parts: a stem, which consists of all but the final digit, and a leaf, the final digit. The stems are ordered from lowest to highest and arranged in a vertical column. The leaves are arranged in increasing order out from the appropriate stems.

histogram

shows each interval of values as a bar. the heights of the bars show the frequencies of values in each interval. 

statistic 

is a number that describes some characteristics of a sample 

parameter

is a number that describes some characteristics of a population 

resistant measure

a statistical measure that isn’t sensitive to extreme values

the median 

the midpoint of a distribution, the number such that about half the observations are smaller and about half are larger

range

distance between the minimum value and the maximum value 

standard deviation

measures the typical distance of the values in a distribution from the mean. 

variance

average squared deviation

quartiles

divide the ordered data set into four groups having roughly the same number of values

first quartile Q1

median of the data values that are to the left of the median in the ordered list 

third quartile Q3

is the median of the data values that are to the right of the median in the ordered list

interquartile range (IQR) 

distance between the first and third quartiles of a distribution 

five number summary

distribution of quantitative data consists of the minimum, the first quartile Q1, the third quartile Q3, and the maximum 

boxplot

is a visual representation of the five-number summary

back to back stemplot

used to compare the distribution of a quantitative variable in two groups. The leaves are placed in order on each side of the common stem.

splitting stems

dividing each stem in a stemplot into two (or more) parts to display the data more clearly and show the distribution in greater detail.