AP statistics unit 2

Studied by 15 people
0.0(0)
Get a hint
Hint

describing scatter plots

1 / 21

Earn XP

Description and Tags

22 Terms

1

describing scatter plots

direction (positive/negative), form (linear/curved), strength, unusual features

New cards
2

scatterplot on calculator

Stat -> Edit, then 2nd -> Statplot

New cards
3

r

correlation coefficient

New cards
4

r measures

the strength of correlation between two quantitative variables

New cards
5

conditions of r

quantitative, straight enough, no outlier

New cards
6

coeffiricent determination

New cards
7

r² measures

how much of the variation in the y-variable is explained by variation in the x-variable

New cards
8

lurking variable

a variable that could cause changes in x and y that’s not measured

New cards
9

residual

the vertical distance between the point and the line of best fit. Actual – Predicted

New cards
10

line of best fit on calculator

type x’s into L1, y’s into L2. Then, Stat-CALC-8:LinReg(a+bx). If the output says: 𝑦 = 𝑎 + 𝑏x; 𝑎 = 2.3; 𝑏 = 1.1, then the line of best fit is 𝑦 = 2.3 + 1.1x

New cards
11

lie of best fit slope =

r * (SD of y/SD of x)

New cards
12

lie of best fit y-intercept =

mean of y - (mean of x * slope)

New cards
13

regression to the mean

number of SD * r = actual prediction from mean

New cards
14

residual plot on calculator

fter data is entered in L1 and L2, do Stat -> CALC -> 8:LinReg(a + bx).
Then, 2 nd ->Statplot, select Scatterplot. Change the Y-List to RESID by highlighting it and clicking 2 nd -> STAT -> RESID. Then, ZOOM -> 9.

New cards
15

residual plot is random

plot is linear, otherwise probably curved

New cards
16

extrapolation

predicting data beyond domain

New cards
17

influential outlier

point changes r or line of best fit

New cards
18

high leverage

far horizontally

New cards
19

high residual

far vertically

New cards
20

re-expression if

scatter plot is not straight enough

New cards
21

re-expression on calculator

1) Sketch a scatterplot of data. (Straight line = good)
2) Do linear regression on it. Record r and r 2 (r close to 1 or -1 = good. r 2 close to 1 = good)
3) Sketch the residual plot. (Random scatter = good)
4) Take the square root of the y’s and store as a new list √ L2 STO L3
5) Now, redo steps 1-3, using L1 and L3
6) Continue transforming L2 using Log(y), stored in L4, 1/√𝑦, stored in L5, and 1/𝑦 ,
stored in L6, in that order, and keep repeating steps 1-3. If those all fail, try Log(x)
and y, or Log(x) and Log(y)
o On calc: Log L2 STO L4
o On calc: 1/ √ L2 STO L5
o On calc: 1/L2 STO L6
7) Choose which one works best by checking the scatterplot, r,r², and the residual plot
8) Make predictions with your old x's and new y's

New cards
22

graph oscillates

can’t re-express if

New cards

Explore top notes

Note
Studied by 30 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 10 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 6 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 43 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 39 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 3 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 27 people
Updated ... ago
5.0 Stars(1)
Note
Studied by 202 people
Updated ... ago
4.3 Stars(4)

Explore top flashcards

Flashcard32 terms
Studied by 5 people
Updated ... ago
5.0 Stars(1)
Flashcard49 terms
Studied by 3 people
Updated ... ago
5.0 Stars(1)
Flashcard38 terms
Studied by 10 people
Updated ... ago
5.0 Stars(1)
Flashcard35 terms
Studied by 6 people
Updated ... ago
5.0 Stars(1)
Flashcard83 terms
Studied by 1 person
Updated ... ago
5.0 Stars(2)
Flashcard82 terms
Studied by 17 people
Updated ... ago
5.0 Stars(1)
Flashcard58 terms
Studied by 3 people
Updated ... ago
4.0 Stars(1)
Flashcard28 terms
Studied by 3 people
Updated ... ago
5.0 Stars(1)