AP STATS: Chapter 1 review

An Individual

is an object described in a set up data

A Variable

An attribute that can take different values for different individuals

Categorical (Qualitative):

assign labels tat place each individual into a particular group, such as grade labels, races, genders, and zip code

Quantitative Variables

Takes number values that are Quantitative. (Counts or measure)

Discrete

Takes a fixed set of possible values with gap between them. Ex, Number of desks

Continuous

Can take any value in an interval on the number line. Ex. 7-9

Distribution

Its a variable that tells us what value the variables take and show how often it takes those values

Categorical Data

Data that reflects qualitative characteristics

Numerical Data

Data that are naturally numbers-based

Nominal

Involves characteristics or groups, no inherit order or rank. All options have the same value. Usually used for survey questions

Ex. Color of the cars your classmates drive, gender, ethnicity

Ordinal

Describes categories, but have a natural rank order. Can’t numerically tell the difference, but could logically rank them.

Ex. Income intervals (range), levels of agreement, levels of satisfaction.

Interval

Level data are naturally measured in numbers, they have an inherit order and have equal spaces between points. The 0 point is not needed (arbitrary) and does not have an absolute 0.

Ex. Credit score, Gmat Score, Temp.

Ratio

Numerical ordered and equal distance between points. Ordered data with an absolute 0. Ex. Weight, height, length, temp in Kalvin, and length of time.

Simple Random Sampling

Chosen by chance and each member of the population has equal chance

(RS)- Larger sampling

(SRS)- smaller sampling

Systematic Sampling

Picking the every nth to sample

Stratified Sampling

Similar Characteristics

Clustered sampling

Geographic separation

Convivence sampling

Biased Sampling

Ex. asking your family their income

Going to your friends lunch and surveying

Circle(pie) Graph

Only used in categorical Data

• Small set of data used

Bar Graph

Only used in categorical data

• Small set of data

Dot Plot

Used for Ratio and Interval Data

• Small and median set of data

Stem and Leaf Display

Used in Ratio and Interval data

• Small and median set of Data and can be converted from a dot plot or histogram

(Frequency) Histogram

Used small to large set of data

Relative Frequency Histogram (percentage)

Uses small to large set of data

• All data is supposed to add up to 100

Box Plot

Contains a 5 number summary and all data has equal amount (25%)

• Uses median to small data set

Central Tendency

Mean, median, and mode

Distribution of Data Set: SHAPE

Normal, Skewness, uniform in context

Distribution of Data Set: CENTER

Median, mean, and mode in context

Distribution of Data Set: VARIABILITY

Range, IQR, Outliers (left/right)