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Here is the distribution of the adjusted gross income (in thousands of dollars)

ID: 3207587 • Letter: H

Question

Here is the distribution of the adjusted gross income (in thousands of dollars) reported on individual federal income tax returns in a particular year. (Round your answers to three decimal places.)

(a) What is the probability that a randomly chosen return shows an adjusted gross income of $30,000 or more?

(b) Given that a return shows an income of at least $30,000, what is the conditional probability that the income is at least $100,000?

*Only need part b.

Income < 15 15-29 30-99 100-199 200 Probability 0.249 0.216 0.385 0.106 0.044

Explanation / Answer

let us assume you have 100 people who follow the expected statistics.

38 of those people will have income 30-99
10 of those people will have income >100

so 48 of the 100 people have incomes > 30 p = 0.48

48 of the people have incomes >30 (given)
of those 10 have income >100

so 10 out of 27 have income >100 p = 10/48 = 0.208