a fair coin is flipped. if the flip results in a head, then a fruit is selected from a basket containing 8 apples, 2 bananas, and 6 cantaloups. if the flip results in a tail, then a fruit is selected from a basket containing 6 apples and 4 bananas. what is the probability that the flip resulted in tails, given that the fruit selexted is a banana g

Respuesta :

Solution :

We have given two baskets :

[tex]$H_1$[/tex] : 8 apples + 2 bananas + 6 cantaloupes = 16 fruits

[tex]$H_2$[/tex] : 6 apples + 4 bananas = 10 fruits

A fair coin is made to flipped. If the [tex]\text{flip}[/tex] results is head, then the fruit is selected from a basket [tex]$H_1$[/tex].

If the flip results in tail, then the fruit is selected from the basket [tex]$H_2$[/tex].

Probability of head P(H) = [tex]1/2[/tex]

Probability of tail P(T) = [tex]1/2[/tex]

if given event is :

B = selected fruit is BANANA

We have to calculate : P(T|B)

Probability of banana if the flip results is head P(B|H) = [tex]$\frac{2}{16}$[/tex]

Probability of banana if the flip results is tail P(B|T) = [tex]$\frac{4}{10}$[/tex]

From the Bayes' theorem :

Probability of flip results is tail when selected fruit is BANANA.

[tex]$P(T|B) = \frac{P(B|T)\ P(T)}{P(B|T) \ P(T) + P(B|H)\ P(H)}$[/tex]

            [tex]$=\frac{\frac{4}{10} \times \frac{1}{2}} {\frac{4}{10} \times \frac{1}{2} + \frac{2}{16} \times \frac{1}{2}}$[/tex]

            [tex]$=\frac{\frac{1}{5}}{\frac{1}{5}+\frac{1}{16}}$[/tex]

            [tex]$=\frac{\frac{1}{5}}{\frac{21}{80}}$[/tex]

            [tex]$=\frac{16}{21}$[/tex]

∴  [tex]$P(\ T|B\ )=\frac{16}{21}$[/tex]