Of 800 people surveyed, 420 were male, and 325 had cell phones. Of those with cell phones, 200 were female. What is the probability that a person surveyed was either male or had a cell phone?
2 Answers
Probability of a male being surveyed:
Probability of person having cell phone:
Probability of being a male with a cell phone:
Explanation:
Now simplify the fraction:
This is the probability of surveying a male.
Now, let’s find the probability of surveying a person with a cell phone. We do the same process as above:
The probability of surveying a male with a cellphone:
So
Hope this helps!
The probability is 31/40, or 0.775 (77.5%).
Explanation:
Let
Let
Then:
#"P"(M uu C) = "P"(M) + "P"(C) - "P"(M nn C)#
Of the 800 people surveyed, the number of people who are male is 420. Thus,
#"P"(M) = 420/800#
Of the 800 people surveyed, the number of people who have a cell phone is 325. Thus,
#"P"(C) = 325/800#
Of the 325 people who have cell phones, 200 are female. This means the remaining 125 people with cell phones are male. Thus,
#"P"(M nn C) = 125/800#
Putting it all together:
#"P"(M uu C) = "P"(M) + "P"(C) - "P"(M nn C)#
#color(white)("P"(M uu C)) = 420/800 + 325/800 - 125/800#
#color(white)("P"(M uu C)) = 620/800#
#color(white)("P"(M uu C)) = 31/40" " = 77.5%#