Goodness of Fit
•A marketer is planning to introduce a new product to the market but she is not sure about the color of the package the product should be sold in. To know if consumers have a preference in terms of color of packaging she conducts a pilot experiment using an alpha level of .05. The number of products sold for each color is provided in the chart below:ColorBlueGreenRedYellow# Sold30203515

Goodness of Fit
•
H
0
: the population proportions are equal
•
H
a
: the population proportions are not equal
Color
Blue
Green
Red
Yellow
# Expected
# Sold
25
30
25
20
25
35
25
15

2

Test of Independence
•
We want to know if the column variable is independent of the
row variable.
–
H
0
: the column variable is independent of the row variable
–
H
a
: the column variable is not independent of the row variable
•
How does it work?
–
Select a random sample and record the observed frequencies for each
cell
–
Compute the expected frequency for each cell
–
Compute the test statistic using the difference between the expected
frequency and observed frequency in each category

Test of Independence
•
𝑒
??


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- Fall '17
- AMHET KOKSUEL