Respuesta :

Answer:

Hence,

P(A∪B)=0.89

Step-by-step explanation:

As we are given that:

A and B are dependent events.

If P(A|B)=0.55 and P(B)=0.2 .

AS we know that:

P(A)+P(B)=1

⇒ P(A)+0.2=1

⇒ P(A)=1-0.2

⇒ P(A)=0.8.

Also we know that:

[tex]P(A|B)=\dfrac{P(A\bigcap B)}{P(B)}\\\\\\i.e.\\\\0.55=\dfrac{P(A\bigcap B)}{0.2}\\\\P(A\bigcap B)=0.55\times 0.2\\\\P(A\bigcap B)=0.11[/tex]

Hence,

[tex]P(A\bigcup B)=P(A)+P(B)-P(A\bigcap B)\\\\P(A\bigcup B)=0.8+0.2-0.11\\\\P(A\bigcup B)=0.89[/tex]

Hence,

P(A∪B)=0.89

Answer:

[tex]P(A \cup B)[/tex] = 0.89

Step-by-step explanation:

Using the formula:

[tex]P(\frac{A}{B}) = \frac{P(A \cap B)}{P(B)}[/tex]           ....[1]

where, A and B are events.

As per the statement:

Suppose A and B are dependent events.

If [tex]P(\frac{A}{B})=0.55[/tex] and P(B) = 0.2

Substitute these in [1] we get;

[tex]0.55 = \frac{P(A \cap B)}{0.2}[/tex]

Multiply both sides by 0.2 we have;

[tex]0.11 = P(A \cap B)[/tex]

We know that:

[tex]P(A)+P(B) = 1[/tex]

⇒[tex]P(A) = 1-P(B)[/tex]

⇒[tex]P(A) = 1-0.2 = 0.8[/tex]

We have to find [tex]P(A \cup B)[/tex]

[tex]P(A \cup B) = P(A)+P(B) -P(A \cap B)[/tex]

Substitute the given values we have;

[tex]P(A \cup B) = 0.8+0.2-0.11 = 1.0-0.11 = 0.89[/tex]

Therefore, the value of  [tex]P(A \cup B)[/tex] is, 0.89