Question 263819
J.D. Power and Associates says that 60 percent of car buyers now use the Internet for research and price comparisons. 
(a) Find the probability that in a sample of 8 car buyers, all 8 will use the Internet;
Ans: 0.6^8
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(b) at least 5
P(5<= x <= 8) = 1 - binomcdf(8,0.6,4) = 0.5941
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(c) more than 4.
P(5<= x <=8) = 0.5941
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(d) Find the mean and standard deviation of the probability distribution.
mean = np = 8*0.6 = 4.8
std = sqrt(npq) = sqrt(4.8*0.4) = 1.3856....
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(e) Sketch the PDF (using Excel or Appendix A) and describe its appearance (e.g., skewness).
Flater to the left of the mean because p > 0.5
Other?
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Cheers,
Stan H.
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