According to the general equation for conditional probability, if [tex]P\left(A \cap B^{\prime}\right)=\frac{2}{9}[/tex] and [tex]P(B)=\frac{1}{3}[/tex], what is [tex]P\left(A \mid B^{\prime}\right)[/tex]?

A. [tex]\frac{1}{3}[/tex]
B. [tex]\frac{1}{6}[/tex]
C. [tex]\frac{5}{6}[/tex]
D. [tex]\frac{2}{3}[/tex]



Answer :

To find [tex]\( P(A \mid B') \)[/tex], we use the definition of conditional probability. The conditional probability [tex]\( P(A \mid B') \)[/tex] is given by:

[tex]\[ P(A \mid B') = \frac{P(A \cap B')}{P(B')} \][/tex]

### Step 1: Calculate [tex]\( P(B') \)[/tex]

Since [tex]\( P(B) = \frac{1}{3} \)[/tex], the probability of the complement of [tex]\( B \)[/tex], denoted as [tex]\( B' \)[/tex], is:

[tex]\[ P(B') = 1 - P(B) = 1 - \frac{1}{3} = \frac{2}{3} \][/tex]

### Step 2: Find [tex]\( P(A \cap B') \)[/tex]

From the problem, we are given that:

[tex]\[ P(A \cap B') = \frac{2}{9} \][/tex]

### Step 3: Plug values into the conditional probability formula

Now, we can substitute the values into the formula:

[tex]\[ P(A \mid B') = \frac{P(A \cap B')}{P(B')} = \frac{\frac{2}{9}}{\frac{2}{3}} \][/tex]

### Step 4: Simplify the fraction

To simplify:

[tex]\[ P(A \mid B') = \frac{\frac{2}{9}}{\frac{2}{3}} = \frac{2}{9} \times \frac{3}{2} = \frac{2 \cdot 3}{9 \cdot 2} = \frac{6}{18} = \frac{1}{3} \][/tex]

Thus, the conditional probability [tex]\( P(A \mid B') \)[/tex] is [tex]\( \frac{1}{3} \)[/tex].

### Answer:

The correct answer is:
A. [tex]\( \frac{1}{3} \)[/tex]