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A CBS News poll conducted June 10 and 11, 2006, among a nationwide random sample of 651 adults,
asked those adults about their party affiliation (Democrat, Republican or none) and their opinion
of how the US economy was changing ("getting better," "getting worse" or "about the same").
The results are shown in the table below.
better same worse
Republican 38 104 44
Democrat 12 87 137
none 21 90 118
(a) P(Republican) = 0.2857 correct
(b) P(worse) = 0.4593 correct
(c) P(worse|Republican) =
(d) P(Republican|worse) =
(e) P(Republican and worse) =
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
(c) P(worse|Republican)
They want you calculate this CONDITIONAL probability.
It is the fraction, whose numerator is the number of Republicans in the Table
in the column "worse" (44), related to the total of Republicans (38 + 104 + 44).
P = = = 0.2366 (rounded). ANSWER
(c) P(Republican|worse)
They want you calculate this CONDITIONAL probability.
It is the fraction, whose numerator is the number of Republicans in the Table
in the column "worse" (44), related to the total in column "worse" (44 + 137 + 118).
P = = = 0.1472 (rounded). ANSWER
(e) P(Republican and worse)
This probability is the fraction, whose numerator is the number in the Table
in the in the intersection of the row "Republican" and the column "worse" (44).
The denominator is the total of people in the table (38 + 104 + 44 + 12 + 87 + 137 + 21 + 90 + 118) = 651.
P = = = 0.0676 (rounded). ANSWER
Solved.