AP Stats - Sept. 19

Ch. 1

100

What is the five-number summary?

What is the five-number summary?

Minimum, Q1, Median, Q3, Maximum

200

If knowing the value of one variable helps predict the value of another variable, we say those variables have....

If knowing the value of one variable helps predict the value of another variable, we say those variables have....an association

300

pg. 21 #15 (a)

The given percentages are for separate age groups, %'s given are not part of the same "whole"

400

pg. 43 #49 (a) and (b)

a) Students probably rounded their answers (some probably also exaggerated)

b) Yes; center for women (175 mins) is greater than for men (120 mins)

Ch. 2

300

A standardized score, also known as a ________, can be found by: (give the formula)

A standardized score, also known as a z-score, can be found by:

z = (x - mean) / standard deviation

400

What are 5 ways of describing a distribution of quantitative data? Give an example for each.

What are 5 ways of describing a distribution of quantitative data? Give an example for each.

Shape (right/left-skew, describe peaks/gaps)

Outliers (Q1-1.5*IQR or Q3-1.5*IQR)

Center (mean/median)

Variability (SD/variance)

500

Explain how adding/subtracting/multiplying/dividing each observation by a constant impacts:

-center

-location

-variability

-shape

for +/- constant A:

Center/Location: +/- A, Shape/Variability: No Change

for * by A:

Center/Location/Variability: *A, Shape: No Change

Ch. 3

100

pg. 198 #71

a)

200

pg. 202 #3.3(b)

residual = 65,000 - 76,832 = -11,832

The teacher has driven 11,832 fewer miles than predicted based on the age of the car

300

pg. 202 #R3.3 (a)

y-hat = 3704 + 12,188x

400

What do r and r² represent? 

What do they mean?

r = correlation coefficient = strength and direction of a relationship between two variables

r² = coefficient of determination = measures how well a model's independent (explanatory) variable explains the variation in its dependent (response) variable

500

What's the formula for slope in the context of a LSRL?

b = r*(s_y/s_x)

Ch. 4

100

When we take a census, we attempt to collect data from...

When we take a census, we attempt to collect data from...

every individual in the population

200

Explain the difference between the types of inference that can usually be made from an observational study and an experiment.

Explain the difference between the types of inference that can usually be made from an observational study and an experiment.

Experiment: Inference can be made about a population (random selection) and about cause and effect (random assignment of treatments).

Obs. Study: Inference can only be made about a population

300

pg. 280 #T4.7

d) a stratified sample from the cities and towns in the market area

400

pg. 279 #R4.7 (a)

Experimental Units: potatoes

Explanatory: storage method and time from slicing until cooking

Response: ratings of color and flavor

Treatments: 1) fresh/immediately, 2) fresh/after an hour, 3) room temp/immediately, 4) room temp/after an hour

500

pg. 282 #T4.14 (b) and (c)

b) if subjects all get caffeine the second time, researchers won't know if increase is due to caffeine or practice with the task

c) yes (...)