4. A student is chosen at random from the student body at a given high school. The probability that the

student selects Math as the favorite subject is 1/4. The probability that the student chosen is a junior is

116/459. If the probability that the student selected is a junior or that the student chooses Math as the

favorite subject is 47/108, what is the exact probability that the student selected is a junior whose

favorite subject is Math?

Respuesta :

Answer:

The exact probability that the student selected is a junior whose  favorite subject is Math is [tex]\frac{124}{459}[/tex].

Step-by-step explanation:

Let the following events represents by the alphabets A and B.

A: Student selects Math as the favorite subject

B: Student chosen is a junior

The probability that the  student selects Math as the favorite subject is 1/4.

[tex]P(A)=\frac{1}{4}[/tex]

The probability that the student chosen is a junior is

[tex]P(B)=\frac{116}{459}[/tex]

The probability that the student selected is a junior or that the student chooses Math as the  favorite subject is 47/108.

[tex]P(A\cup B)=\frac{47}{108}[/tex]

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

[tex]\frac{47}{108}=\frac{1}{4}+\frac{116}{459}-P(A\cap B)[/tex]

[tex]P(A\cap B)=\frac{1}{4}+\frac{116}{459}-\frac{47}{108}=\frac{31}{459}[/tex]

The exact probability that the student selected is a junior whose  favorite subject is Math is

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

[tex]P(\frac{B}{A})=\frac{\frac{31}{459}}{\frac{1}{4}}=\frac{124}{459}[/tex]

Therefore the exact probability that the student selected is a junior whose  favorite subject is Math is [tex]\frac{124}{459}[/tex].

The exact probability that the student selected is a junior whose favourite subject is maths is 124/459

What is probability?

It is defined as the ratio of the number of favourable outcomes to the total number of outcomes, in other words, the probability is the number that shows the happening of the event.

We have:

The probability that the student selects Maths the favourite subject:

P(A) = 1/4

The probability that the student chosen is a junior:

P(B) = 116/459

The probability that the student selected is a junior or that the student chooses maths the favourite subject:

P(A∪B) = 47/108

We know:

P(A∩B) = P(A) + P(B) _P(A∪B)

P(A∩B) = 1/4 + 116/459 - 47/108

P(A∩B) = 31/459

The exact probability that the student selected is a junior whose favourite subject is maths:

P(B|A) = P(A∩B) /P(A)

= (31/459)/(1/4)

= 124/459

Thus, the exact probability that the student selected is a junior whose favourite subject is maths is 124/459

Learn more about the probability here:

brainly.com/question/11234923

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