I had the following to solve:
51% of all domestic cars being shipped have power windows. If a lot contains
five such cars:
a. what is probability that only one has power windows?
b. what is probability that at least one has power windows?
I solved each of these problems in two ways, one using std probability
theory and one by using a binomial distribution. I seemingly had no problem
w/part b., but in part a. the probability theory did not seem to produce the
correct answer. I have listed these below. What is wrong w/the probability
equation listed below? Also is my answer to part b. correct?
a. Randomly Draw Five Samples (Cars)
Independent Events Only 1 w/Power Windows
P{Only 1 Power} = P (Power) x P (NotPower) x P (NotPower) x P
(NotPower) x P (NotPower)
0.51 0.49 0.49 0.49 0.49 =
Also Solve Using BINOMDIST Function in Excel
n 5
? 0.51 Success - PW
x 1
p(x) 0.14700
b. At least 1 w/Power Windows
P {At Least 1} = 1 - P {0}
P {0} = P (NotPower) x P (NotPower) x P (NotPower) x P (NotPower) x
P (NotPower)
0.49 0.49 0.49 0.49 0.49
Prob 0 0.02825
1 - 0.02825
At least 1 0.97175
Also Solve Using BINOMDIST Function in Excel ~ 97%
n 5
? 0.49 Success - No Power
x 0
p(x) 0.02825
1 - 0.028247525
97%
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