Question

In a population of fruit flies, 37.5% possess a particular trait, T. Suppose 25% of the females possess the trait, and that the population is composed of equal numbers of males and females. If a fruit fly is selected at random from the population, and it possesses the trait T, what is the probability that it is female?

Answer 1

Answer:

Data given:

In a population of fruit flies - 37.5% possess a particular trait, T.

It is given that 25% of the females possess the trait.

The population is composed of equal numbers of males and females.

Probability that a fruit fly selected at random from the population, and it possesses the trait, is a female = ?

Now, using the above information, we can find the required probability as -

1. The population is composed of equal numbers of males and females.

   It is given that 25% of the females possess the trait.

:. Percentage of females relative to total population that possesses the trait 0.25 x 0.5

$=0.125$

Since it is given that the randomly selected fruit fly is found to possess the the trait, T, therefore the probability of the selected fruit fly to be a female can be computed as -

P(Female Possesses trait) Percentage of females relative to total population that possesses the trait Total percentage of population that possesses the trait
  

  

033

Thus, the probability that a fruit fly selected at random from the population, and it possesses the trait, is a female is approximately 0.33 .