Wednesday, July 8, 2009

Practice for tomorrow's exam

Consider the contingency table below. The columns represent A and A-bar, the complement of A, while the rows represent B and its complement B-bar. The numbers are the number of element in each intersection.

_______________A____A-bar_____row totals

B_____________25________________75
B-bar_________________50___________
col. totals___90_____________________grand total

Use the numbers from the filled in table to find the cardinalities in each section.

Cardinality in white section =
Cardinality in yellow section =
Cardinality in gray section =
Cardinality in cyan section =

Answers in the comments.

1 comment:

Prof. Hubbard said...

Here is the table all filled in.

____________A____A-bar__row totals
B__________25_____50______75
B-bar______65_____50_____115
col. total_90____100_____190 grand total

Cardinality in white section = 50
Cardinality in yellow section = 65
Cardinality in gray section = 25
Cardinality in cyan section = 50

The 50 in white is the 50 from the second row and second column.

The 50 in the cyan is the first row and second column.