During a flu epidemic, 35% of the school's students have the flu. Of those with the flu, 90% have high
temperatures. However, high temperatures are possible for people who do not have the flu. It is estimated that
12% of those without the flu have high temperatures.
If a student has a high temperature, what is the probability that the student has the flu?

Respuesta :

Answer: 0.8015

Step-by-step explanation:

Let F= event that a person has flu

H= event that person has a high temperature.

As per given,

P(F) =0.35

Then P(F')= 1- 0.35= 0.65               [Total probability= 1]

P(H | F) = 0.90

P(H|F') = 0.12

By Bayes theorem, we have

[tex]P(F|H)=\dfrac{P(F)\timesP(H|F)}{P(F)\timesP(H|F)+P(F')\timesP(H|F')}\\\\=\dfrac{0.35\times0.90}{0.35\times0.90+0.65\times0.12}\\\\=\dfrac{0.315}{0.315+0.078}\approx0.8015[/tex]

Required probability = 0.8015