SOLUTION: Within the United States, approximately 11.25% of the population is left-handed. Of the males, 12.6% are left-handed, compared to only 9.9% of the females. Assume the probability

Algebra ->  Probability-and-statistics -> SOLUTION: Within the United States, approximately 11.25% of the population is left-handed. Of the males, 12.6% are left-handed, compared to only 9.9% of the females. Assume the probability       Log On


   

Question 674362: Within the United States, approximately 11.25% of the population is left-handed. Of the males, 12.6% are left-handed, compared to only 9.9% of the females. Assume the probability of selecting a male is the same as selecting a female.What is the probability that a person is a right handed male?
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!
Within the United States, approximately 11.25% of the population is left-handed. Of the males, 12.6% are left-handed, compared to only 9.9% of the females. Assume the probability of selecting a male is the same as selecting a female.What is the probability that a person is a right handed male?
We start with this chart.  We assume 50% of the population are male
and 50% of the population are female.  
         
----------------------------------------
        |  Right |   Left    |         |
        | Handed |  Handed   |  Totals |
--------|--------|-----------|---------|
Male    |        |           |   50%   |
--------|--------|-----------|---------|
Female  |        |           |   50%   |
--------|--------|-----------|---------|
Totals  |        |  11.25%   |  100%   |
--------|--------|-----------|---------|

We can fill in the percentage of the people who are
Right handed by subtracting 11.25% from 100%.
100% - 11.25% = 88.75%

----------------------------------------
        |  Right |   Left    |         |
        | Handed |  Handed   |  Totals |
--------|--------|-----------|---------|
Male    |        |           |   50%   |
--------|--------|-----------|---------|
Female  |        |           |   50%   |
--------|--------|-----------|---------|
Totals  | 88.75% |  11.25%   |  100%   |
--------|--------|-----------|---------|

>>Of the males, 12.6% are left-handed,<<

So we take 12.6% of 50% and get 6.3%.  So we fill that
in for the percentage of the population who are 
left-handed males.

----------------------------------------
        |  Right |   Left    |         |
        | Handed |  Handed   |  Totals |
--------|--------|-----------|---------|
Male    |        |   6.3%    |   50%   |
--------|--------|-----------|---------|
Female  |        |   4.95    |   50%   |
--------|--------|-----------|---------|
Totals  | 88.75% |  11.25%   |  100%   |
--------|--------|-----------|---------|

>> compared to only 9.9% of the females (who are left-handed)<<

We don't need that information because we can just subtract
11.25% - 6.3% and get 4.95% or as a check we take 9.9% of 50% 
and get 4.95%.  So, either way we get it we fill that
in for the percentage of the population who are 
left-handed females.

The two right-handed slots can be filled in by subrtacting
50% - 6.3% = 43.7%  and 50% - 4.95% = 45.05%.

----------------------------------------
        |  Right |   Left    |         |
        | Handed |  Handed   |  Totals |
--------|--------|-----------|---------|
Male    | 43.7%  |   6.3%    |   50%   |
--------|--------|-----------|---------|
Female  | 45.05% |   4.95    |   50%   |
--------|--------|-----------|---------|
Totals  | 88.75% |  11.25%   |  100%   |
--------|--------|-----------|---------|

What is the probability that a person is a right handed male?

Answer:  43.7% = 0.437

Edwin