# AP Stats - Unit 1

Studied by 40 People
0.0(0)
get a hint
hint

frequency

1/45

### There's no tags or description

Looks like no one added any tags here yet for you.

## Studying Progress

New cards
45
Still learning
0
Almost done
0
Mastered
0
45 Terms
New cards

frequency

count

New cards
New cards

relative frequency

Percentage or proportion of the whole number of data.

New cards
New cards

pie chart

a circular chart divided into triangular areas proportional to the percentages of the whole

New cards
New cards

bar graph

a graph that uses vertical or horizontal bars to show comparisons among two or more items

spaces between the bars

categorical variables on the x-axis

New cards
New cards

two-way table

A table containing counts for two categorical variables. It has r rows and c columns.

New cards
New cards

marginal relative frequency

Gives the percent or proportion of individuals that have a specific value for one categorical variable on a two-way table

New cards
New cards

joint relative frequency

gives the percent or proportion of individuals that have a specific value for one categorical variable and a specific value for another categorical variable on a two-way table

New cards
New cards

conditional relative frequency

gives the percent or proportion of individuals that have a specific value for one categorical variable among individuals who share the same value of another categorical variable (the condition)

New cards
New cards

side-by-side bar graph

Used to compare the distribution of a categorical variable in each of several groups. For each value of the categorical variable, there is a bar corresponding to each group. The height of each bar is determined by the count or percent of individuals in the group with that value.

New cards
New cards

segmented bar graph

a bar graph stacked on top of another bar graph (not mosaic)

New cards
New cards

mosaic plot

a modified segmented bar graph in which the width of each rectangle is proportional to the number of individuals in the corresponding category

New cards
New cards

association

between two variables if knowing the value of one variable helps predict the value of another

New cards
New cards

Dot Plot

a graphical device that summarizes data by the number of dots above each data value on the horizontal axis

New cards
New cards

stem plot

A graphical display of quantitative data that involves splitting the individual values into two components

represents frequency of data points

New cards
New cards

histogram

A graph of vertical bars representing the frequency distribution of a set of data.

New cards
New cards

symmetric

Being equal or the same in size, shape, and relative position

New cards
New cards

skewed left

the tail to the left of the peak is longer than the tail to the right of the peak

New cards
New cards

skewed right

the tail to the right of the peak is longer than the tail to the left of the peak

New cards
New cards

shape

distribution of data (skew)

New cards
New cards

center

median/middle

New cards
New cards

variability

in a set of numbers, how widely dispersed the values are from each other and from the mean (range)

New cards
New cards

outliers

Numbers that are much greater or much less than the other numbers in the set

New cards
New cards

mean > median

skewed right

New cards
New cards

mean = median

symmetric

New cards
New cards

mean < median

skewed left

New cards
New cards

standard deviation

a measure of variability that describes an average distance of every score from the mean

New cards
New cards

Interquartile Range (IQR)

A measure of variability, defined to be the difference between the third and first quartiles.

New cards
New cards

first quartile

the median of the lower half of the data set

New cards
New cards

third quartile

the median of the upper half of the data set

New cards
New cards

resistant

relatively unaffected by extreme observations

median and IQR

New cards
New cards

1.5 x IQR rule

identifies outliers as an individual value that falls more than 1.5 x IQR above the 3rd quartile or below the 1st quartile.

New cards
New cards

box plots

A data display that shows the five-number summary. The whiskers, stretching outward from the first quartile and third quartile as shown below, are no longer than 1.5 times the interquartile range (IQR). Outliers beyond that are marked separately.

New cards
New cards

five-number summary

minimum, 1st quartile, median, 3rd quartile, maximum

New cards
New cards

percentiles

# values ( = or < ) the given value / total values

New cards
New cards

standardized scores (z score)

Known population standard deviation or variance?

The Z score give you the exact location of the score within the distribution

Z scores can be positive or negative

New cards
New cards

cumulative relative frequency

The term applies to an ordered set of observations from smallest to largest.

The sum of the relative frequencies for all values that are less than or equal to the given value.

New cards
New cards

transform data

• mean, 5#, percentiles change

• range, IQR, SD dont

multiply and divide

• center, location, variability change

shape never changes

New cards
New cards

density curve

a curve that is always on or above the horizontal axis and has area exactly 1 underneath it

estimates the proportion of observations that falls in an interval of values

New cards
New cards

mean of the density curve

the balance point, at which the curve would balance if made of solid material

New cards
New cards

standard deviation of a density curve

σ (sigma)

New cards
New cards

normal distributions

data representation with a distinctive bell-shaped curve, symmetric about the mean

New cards
New cards

mean and median on density curves

equal if symmetric mean is pushed toward the long tail if skewed

New cards
New cards

68-95-99.7 rule (empirical rule)

Within a normal distribution, 68% of scores will fall within +/- 1 standard deviation (SD) of the mean; 95% within 2 SDs of the mean; and 99.7% within 3 SDs of the mean. (Almost all scores will fall between 3 SDs of the mean.)

New cards
New cards

normal probability plot

Used to assess normality. if it has a linear form

New cards
New cards

Skewed Probability Distribution

skewed left - curves on the right/ top

skewed right - curves on the left/bottom

New cards