Respuesta :
Answer:
Option d - 720/750 ≈ 0.96
Step-by-step explanation:
Given : Of 750 people surveyed, 330 were male and 640 had cell phones. Of those with cell phones, 390 were female.
To find : What is the probability that a person surveyed was either male or had a cell phone?
Solution :
Let M be the number of males i.e. M=330
Let C be the number of cell phones i.e C=640
Total number of people = 750
Of 750 people surveyed, 330 were male
The probability of male is
[tex]P(M)=\frac{330}{750}[/tex]
Of 750 people surveyed, 640 had cell phones
The probability of cell phones is
[tex]P(C)=\frac{640}{750}[/tex]
Of those with cell phones, 390 were female.
i.e. reaming were male so 640-390=250
So, Probability of male and cell phone is
[tex]P(M\cap C)=\frac{250}{750}[/tex]
We have to find, the probability that a person surveyed was either male or had a cell phone i.e. [tex]P(M\cup C)[/tex]
Using formula,
[tex]P(M\cup C)=P(M)+P(C)-P(M\cap C)[/tex]
Substitute the values,
[tex]P(M\cup C)=\frac{330}{750}+\frac{640}{750}-\frac{250}{750}[/tex]
[tex]P(M\cup C)=\frac{330+640-250}{750}[/tex]
[tex]P(M\cup C)=\frac{720}{750}[/tex]
[tex]P(M\cup C)=0.96[/tex]
Therefore, Option d is correct.
