1.The max weight an elevator can carry is 700 kg.

Let the probability distribution of human weight be Unit{71,72,...,90}.

8 people (who's weight is independent) get on the elevator.

A)Find the upper limit to the probability that the total weight will exceed the maximum permitted using Markov's inequality.

B)Find the upper limit to the probability that the total weight will exceed the maximum permitted using Chebyshev's inequality.

2.Let $\displaystyle X_n$ be the number of tails after $\displaystyle n$ tries,

P(tails)=p.

Find n that assures the probability of |$\displaystyle X_n$/n-p|< 0.1 is at least 0.95.

As far as I know in the first question according to Markov's inequality it shold go something like that:

P(X$\displaystyle \geqslant$700)=E(X)/700=80.5/700=0.115,is it correct?

Please correct me if I'm wrong and help me solve the rest.

Thanks in advance