Depression is a mood disorder which is usually associated with significant mental health problems. It is estimated that in the population of ages 15 to 64, 19% of women and 11% of men suffer from depression. Suppose that the ratio between the male and the female populations aged 15 to 64 is 0.79
a) What proportion of this population aged 15 to 64 consists of females?
b) What is the probability that a randomly chosen person of age 15 to 64 suffers from depression?