Question 145233
After a particularly brilliant Super Bowl ad, a company believes that 78% of all adults (18 and older) recognize their brand; therefore 22% do not.
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a. If we sample adults, what’s the probability that the first or the second does not recognize the brand?
P(both do not recognize their brand) = = 0.22^2 = 0.0484
P(both recognize their brand) = 0.78^2 = 0.6084
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Therefore P(one or other does not recognize their brand) = 1-(0.0484 + 0.6084)
= 0.3432
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b. If we sample adults, what’s the probability that the 3rd person asked is the first one who doesn’t recognize the brand? 
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Prob (do followed by do followed by don't) = (0.78)(0.78)(0.22) = 0.133848..
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Cheers,
Stan H.