Question

Giving a test to a group of students, the grades and gender are summarized below ABCTotalMale1520641Female16121139Total31321780If one student is chosen at random, find the probability that the student was male OR got a/an "C". Round to at least 3 decimal places ____.

Answer 1

The Solution:

Given the table below:

Required:

To find the probability that a student selected at random is a male or got a 'C'.

The required probability is:

`P(a\text{ Male or a C})=P(Male)+P(a\text{ C\rparen}-P(M\cap C)`

In this case,

`\begin{gathered} P(a\text{ Male})=(41)/(80) \\ \\ P(a\text{ C})=(17)/(80) \\ \\ P(M\cap C)=(6)/(80) \end{gathered}`

Substituting, we get

`\begin{gathered} P(a\text{ Male or a C})=(41)/(80)+(17)/(80)-(6)/(80)=(41+17-6)/(80)=(52)/(80)=0.65 \\ \approx0.650 \end{gathered}`

Therefore, the correct answer is 0.650 (3 decimal place)