The table above indicates the number of randomly chosen 4 5, & 6 graders as to
whether their primary goal was to get good grades, to be popular, or to be good at
APexam = 6.97 + .1278 midterm
For every point you get on the miderm, we would expect your AP exam score to be
Example: Fast food sandwiches
X = 1 7 .2 g
sx = 14.6 g
Y = 23.5 g
sy = 16.4 g
b1 = r ( )
Characteristics of the regression line:
1) It is important to correctly indicate the explanatory and response variables.
2) The least squares regression line always passes through the point ( X , Y ) .
3) The slope of the LSRL is
b1 = r
4) The y
Example of a probability table:
28% Rain Sat. and Sun.
18% No Rain Sat. and
Rules of Basic Probability:
2.Su m oftheprobabilitiesforallpossibleoutco m esinasa mplespacemusttotalone
Lesson B2: The Wieland and Liza Problem
Given random variable x
(c is a constant)
Standard deviation (x+y) or difference of standard deviations:
Wieland and Liza have cereal for breakfast each morning. Wieland h
Whenever a regression is run on the calculator, the residuals will be
placed in a list called resid.
To view a residual plot, follow the directions for a scatterplot: press
2nd staplot, turn the desired plot on, choose 1st type of plot, choose
1) Form: linear
2) Direction (positive/ negative)
3) Strength: weak, moderate, strong
We describe the association between two variables.
The Correlation Coefficient:
The correlation coefficient, r, is the statistic that measures the strength and
Standard Deviation Sx or x: The average distance the value of the variable is from the mean
Variance sx2 or x2
Resistant measure: A value that is relatively unaffected by changing a small proportion of the
total number of values
Density curve: Has an area