Here is the distribution of the adjusted gross income in tho

Here is the distribution of the adjusted gross income (in thousands of dollars) reported on individual federal income tax returns in 2008:

A.	What is the probability that a randomly chosen return shows an adjusted gross income of $30,000 or more? Your answer should be accurate to 3 decimal places.

Here is the distribution of the adjusted gross income (in thousands of dollars) reported on individual federal income tax returns in 2008: A. What is the probability that a randomly chosen return shows an adjusted gross income of $30,000 or more? Your answer should be accurate to 3 decimal places. B.Given that a return shows an income of at least $30,000, what is the conditional probability that the income is at least $75,000? (Give your answer to 4 decimal places.)

Solution

(A) P(X>=30000) = 0.315+0.18+0.031 =0.526

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(B) P(X>=75000| X>=30000) = P(X>=75000) / P(X>=30000)

=(0.18+0.031)/0.526

=0.4011