
Latin
Latin/Greek Root Words


(Statistics
connection) 

AP Statistics Standards
III. Anticipating Patterns: (continued)
D.
Sampling distributions
8.
Chisquare distribution
IV. Statistical Inference:
B. Tests of significance

Chisquare test for
goodness of fit, homogeneity of proportions, and independence (one
and twoway tables)


Essential Question:
Why would it be useful to have a
quantitative way to test if data fits a particular distribution
instead of merely relying on histograms, box plots, or normal
quantile plots? 
Ch. 13.1 Inference for Tables
 Name
2 instances when a chisquared test can be used.
Note: chi is
pronounced kie (rhymes with pie).
 Goodnessoffit
(tests the Ho that there is no difference between the distribution of sample data and a known distribution )
example
 Inference for 2way
tables (tests the Ho that there is no
relationship between row and column variables)

Describe the shape and
range of the chisquared distribution.
Skewed right, zero to
positive infinity

Determine degrees of freedom for a goodnessoffit
chi squared calculation.
( df = n1)

Calculate the chi
squared statistic.
C^{2} =
S (O  E)^{2} / E
Where:
O = observed
data point
E = expected
 Perform chi squared goodness of fit hypothesis
tests.
Assumptions:
Simple
Random
Sample
Independence:
Observations are assumed to be
independent. Chisquared can't be used to test correlated data
(like matched pairs or panel data).
 Note that the hypotheses for a chisquared test
cannot readily be stated mathematically. They are as follows:
 Null hypothesis: The data's
distribution and the reference distribution are the same.
 Alternative hypothesis: The data's
distribution and the reference distribution are different.

Find pvalues for a chi squared test
using both the table and the TI  83 calculator
Χ^{2 }cdf ( LUD ).
Lower, Upper,
Degrees of freedom
Homefun: 
Read 11.1, Exercises 1, 3, 11, 13, 19, 21 pp.692 to 695


Essential
Question: How
can statistics be applied to genetic analysis in the real world? 
 Describe how the
chisquared test can be used for determining if a set of data is not
randomly distributed assuming that all events are equally probable.
Stats
Investigation: statistical
Analysis of Genome Data  computer lab using Minitab.


Essential
Question: How
can tables containing massive amounts of data be rapidly screened
for relationships between the rows and columns? 
Ch. 13.2
Inference for TwoWay Tables
 Calculate expected
results for tables (p.720 ).
expected =

(
row total ) ( column total ) 
(table total) 
 Calculate chisquared
statistics for tables (p. 723).
 Determine the degrees
of freedom for a chisquared (p. 724).
df = (rows1)(columns1)

Perform hypothesis
tests using chisquared statistics.
 Be able to read
chisquared computer print outs.
Homefun: 
Read 11.2, Exercises 33, 35, 37, 43, 45, 51 pp. 725 to 729
Chapter 11 practice test multiple choice and free respnse, pp. 733 to 735 


