SOLUTION: It is reported that 24% of American households use a cell phone exclusively for their telephone service. In a sample of nine households, find the probability that: a. No h

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Question 1119809: It is reported that 24% of American households use a cell phone exclusively for their telephone service. In a sample of nine households, find the probability that:

a.
No household uses a cell phone as their exclusive telephone service. (Round your answer to 4 decimal places.)

Probability


b.
Exactly 6 households exclusively use a cell phone for telephone service. (Round your answer to 4 decimal places


c.
Find the mean number of households exclusively using cell phones. (Round your answer to 4 decimal places.)

Mean


Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
a. No cell phone for each of 9 is 0.76^9=0.0846
b. This would be 9C3*0.24^6*0.76^3=0.0070. The expected value would be 2.16 (.24*9), so this is a reasonable probability.
c. The expected value above of 2.14 is np, and that is the mean value of houses.