SCENARIO 12-4
A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of 5 memory locations.A check at the end of a day's transactions gave the counts shown in the table to each of the 5 memory locations,along with the number of reported errors.
The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the 5 memory locations differ.
-Referring to Scenario 12-4,the degrees of freedom of the test statistic is
A)4
B)8
C)10
D)448

Question

SCENARIO 12-4
A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of 5 memory locations.A check at the end of a day's transactions gave the counts shown in the table to each of the 5 memory locations,along with the number of reported errors.
  The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the 5 memory locations differ.
-Referring to Scenario 12-4,the degrees of freedom of the test statistic is
A)4 
B)8 
C)10 
D)448

Quizplus · Accepted Answer

The degrees of freedom for the test statistic is the number of observations minus the number of parameters estimated. In this case, there are 449 observations and 1 parameter estimated (the mean). Therefore, the degrees of freedom is 449 - 1 = 448.

SCENARIO 12-4 A Computer Used by a 24-Hour Banking Service Is Supposed