AP Stat final S1

Categorical Data

Descriptor or non numerical value

Misleading graphs

Scale and location of orgin and pictures or icons

A histrogram

is not a bar graph

What is the difference between a bar graph and a mosaic plot

a mosaic plot is a segmented bar graph with widths that are proportional to group size

What is CSOCS

Context, Shape, Outliers, Center, Spread

How do you interpret standard deviation

CONTEXT typically varies by SD from the mean of MEAN

Which measure of center is best to use when there are outliers

Median

Which measure of center is best to use when the distribution is symmetrical

Mean

Which measure of spread is best to use when there are outliers

Inter quartile range

Which measure of spread is best to use when the distribution is symmetrical

Standard deviation

IQR =

Q3 - Q1

Finding outliers using IQR

Q1 - 1.5 (IQR) and Q3 + 1.5 (IQR)

Percentile

Less than or equal to a value

Z-score

(x-mean)/standard deviation

What is z-score

Number of standard deviations above or below the mean

What is relative frequency

Starts at 0% and goes up to 100%, never goes down, never shows value

If you add or subtract from all values in a sample

the center changes

If you multiply or divide by a factor for all values in a sample

the center and the spread change

A density curve

has an area of 1, is above the x-axis, and has a uniform distribution

68-95-99.7 rule

68% of z-scores fall within 1 standard deviation of a normal curve, 99.7% fall within 3

What is the shape of a normal curve

Symmetrical

What does CDUFS stand for

Context, direction, unusal features, form, and strength

What does CDUFS describe

Scatter plots

Response variable goes on what axis

Y

Explanatory variable goes on what axis

X

What is r

Correlation

What is considered a strong correlation

.97

What would increase the value of r

Unusual point close to the line

what is a residual

actual value - predicted

Interpret the y intercept

when x=0 the predicted Y CONTEXT is Y-INT

Interpret the slope

for every X CONTEXT the predicted Y CONTEXT increases or decreases by SLOPE

Linear residual plot

Random scatter

What is S

the standard deviation of residuals

What is r²

the coefficient of determination % or variability

What is a power function

(log x, log y)

What is a exponential function

(x, log y)

What is a cubic function

(x, 3/y)

what is a quadratic function

(x, /y)

What is a bad kind of sample

Convenience or voluntary response sample

What types of samples contain groups

stratified and cluster

What represents an experiment

treatments are applied

What represents the confounding variable

outside component that impacts results

Random assignment vs random selection

assignment establishes causation and selection observes a trend

what is a simulation

imitation of change behavior based on a model

complement rule

probability something will not happen

probabilities should add up

to 1

mutually exclusive

events cannot occur together

p (at least 1) =

1 - p (none)

discrete random variable

x takes on a fixed number of values

What is the 10% rule

n (less than or equal to) 10% of the population

large counts condition

np (less than or = ) 10 and n (1 - p) (less than or = ) 10