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Airjunkie X is a random variable that represents the number of telephone lines in useby the technical support center of a software manufacturer at noon each day. The prob. distribution of X is show below
x 0 1 2 3 4 5
p(x) .35 .2 .15 .15 .10 .05
1. Calculate the expected value (the mean) of X.
(0)(.35)+(1)(.20)+(2)(.15)+(3)(.15)+..... = 1.6
2. Using past records, the staff at the technical support center randomly selected 20 days and found that an average of 1.25 telephone lines were in use at noon on those days. The staff proposes to select another random sample of 1,000 days and computer the average number of telephone lines that were in use at noon on those days. How do you expect the average from this new sample to compare to that of the first sample? Explain