"if one of the 255 subjects is randomly selected, find the probability that the person is over 40 years of age or that they drin
k root beer."
2 answers:
the picture in the attached figure
we know that
The probability of an event is the ratio of the size of the event space to the size of the sample space.
The size of the sample space is the total number of possible outcomes
The event space is the number of outcomes in the event you are interested in.
so
P=size of the event space/size of the sample space
step 1
find the probability that the person is over 40 years
size of the sample size=255
size of the event space=85
P=85/255------> P=1/3
step 2
find the probability that they drink root beer
size of the sample size=255
size of the event space=75
P=75/255------> P=5/17
step 3
find the probability that the person is over 40 years of age or that they drink root beer
so
P=(1/3)+(5/17)-----> P=(17*1+3*5)/51------> P=32/51-----> 0.6275----> 62.75%
therefore
the answer is
32/51 or 62.75%
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