Complete question :
It is estimated 28% of all adults in United States invest in stocks and that 85% of U.S. adults have investments in fixed income instruments (savings accounts, bonds, etc.). It is also estimated that 26% of U.S. adults have investments in both stocks and fixed income instruments. (a) What is the probability that a randomly chosen stock investor also invests in fixed income instruments? Round your answer to decimal places. (b) What is the probability that a randomly chosen U.S. adult invests in stocks, given that s/he invests in fixed income instruments?
Answer:
0.929 ; 0.306
Explanation:
Using the information:
P(stock) = P(s) = 28% = 0.28
P(fixed income) = P(f) = 0.85
P(stock and fixed income) = p(SnF) = 26%
a) What is the probability that a randomly chosen stock investor also invests in fixed income instruments? Round your answer to decimal places.
P(F|S) = p(FnS) / p(s)
= 0.26 / 0.28
= 0.9285
= 0.929
(b) What is the probability that a randomly chosen U.S. adult invests in stocks, given that s/he invests in fixed income instruments?
P(s|f) = p(SnF) / p(f)
P(S|F) = 0.26 / 0.85 = 0.3058823
P(S¦F) = 0.306 (to 3 decimal places)