In: Statistics and Probability
There are 23 families living in the Willbrook Farms Development. Of these families, 10 prepared their own federal income taxes for last year, 5 had their taxes prepared by a local professional, and the remaining 8 by H&R Block.
What is the probability of selecting a family that prepared their own taxes? (Round your answer to 2 decimal places.)
What is the probability of selecting two families, both of which prepared their own taxes? (Round your answer to 4 decimal places.)
What is the probability of selecting three families, all of which prepared their own taxes? (Round your answer to 4 decimal places.)
What is the probability of selecting two families, neither of which had their taxes prepared by H&R Block? (Round your answer to 4 decimal places.)
(a) What is the probability of selecting a family that prepared
their own taxes? (Round your answers to 3 decimal places.)
Probability = Families prepared own taxes/Total Families
10/23 = 0.4347826
(b) What is the probability of selecting two families both of which
prepared their own taxes? (Round your answers to 3 decimal
places.)
After selecting the first person from own tax families there
will only remain 9 own tax family and 22 total families.
Probability = (10 / 23)(9 / 22) = 0.1778656
(c) What is the probability of selecting three families, all of
which prepared their own taxes? (Round your answers to 3 decimal
places.)
Probability = (12 / 24)(11 / 23)(9 / 21) =
0.1024845
(d) What is the probability of selecting two families, neither of
which had their taxes prepared by H&R Block? (Round your
answers to 3 decimal places.)
There are 23-8 = 15 families who have not prepared taxes by H&R department.
The probability of selecting two families from these above 15
families = probability of selecting two families, neither of which
had their taxes prepared by H&R Block.
Probability = (15/ 23)*(14 / 22) = 0.4150198