1.Find the mean and the variance of the uniform probability distribution
given by
f(x) = 1/n for x =1,2,3,4.....,n
[hint: the sum of the first n positive is n(n+10)/2 , and the sum of their
squares is n(n+1)(2n+1)/6]
2.In 1 out 6 cases,material for bulletproof vests fails to meet puncture
standards. If 405 specimens are tested, what does Chebyshev's theorem tell
us about the probability of getting at most 30 or more than 105 cases that
do not meet puncture standard?
老實說第二題我根本就不太懂他要衝蝦米
唉
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