1. An accountant wants to test the hypothesis that the proportion of incorrect transactions at four client accounts is about the same. A random sample of 80 transactions of one client reveals that 21 are incorrect; for the second client, the sample pro- portion is 25 out of 100; for the third client, the proportion is 30 out of 90 sampled; and for the fourth, 40 are incorrect out of a sample of 110. Conduct the test at CY = 0.05.
2. An article in Business Week describes how three online news services now supply Web surfers quick information on developing stories.20 Suppose that a ran- dom sample of users is available from various parts of the country. Data are shown in the table below. Is there evidence that the three Web news services have different success rates at different regions of the country?
|
Google News
|
Northeast
78
|
South
15
|
West
109
|
Midwest
65
|
|
PBS Online
|
115
|
10
|
88
|
50
|
|
New York Times
|
208
|
3
|
52
|
40
|