SOLUTION: The Better Business Bureau settles 65% of complaints it receives involving new car dealers. Suppose a sample of 90 complaints involving new car dealers is selected. Find the prob

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Question 993502: The Better Business Bureau settles 65% of complaints it receives involving new car dealers. Suppose a sample of 90 complaints involving new car dealers is selected. Find the probability that Better Business Bureau settles less than 62 of these complaints
Please please help me
Thank you so much
Found 2 solutions by Boreal, stanbon:
Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website!
Looking at the problem, the expected number of complaints solved for 90 would be 90*0.65=58.5, and that is less than 62. Therefore, the probability will be fairly large that they settle fewer than 62.
The probability is <62/90=0.6888 (repeat)
1 sample proportion
z=(0.6888-0.65)/sqrt{ (0.65)(0.35)/90}
denominator is 0.0503
z= 0.03888/0.05
We want the probability that z is < than that number, The probability will be more than a half, since the sample proportion is greater than the purported probability.
That is 0.7817

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
The Better Business Bureau settles 65% of complaints it receives involving new car dealers. Suppose a sample of 90 complaints involving new car dealers is selected. Find the probability that Better Business Bureau settles less than 62 of these complaints
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Binomial Problem with n = 90 and p(settle) = 0.65
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P(x < 62) = binomcdf(90,0.65,61) = 0.7224
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Cheers,
Stan H.