Recent content by RsMath

yes , I meant expectation(average) "show that the expected maximum distance is not greater than O(logn)

If we have a person who in t=0 (time) is standing on x=0 . every one second (t=t+1) in without any dependency on previous steps : he moves to right(x=x+1) in probability = 1/4 and he moves to left (x=x-1) in probability = 1/4 . and he goes back to x=0 in probability = 1/2 . show that...

thanks tedbradly. you have found the variance of the mean by dividing by 3 . shouldn't it be : var(x+x+x) = var(x)+var(x+x)+2*cov(x,x+x) = var(x)+4*var(x)+2*(E(x(x+1))-E(x)*E(x+x) = 9*var(x) ?? and not var(x)/3 ? I just need to make sure .

I have these two question I hope someone could check them out for me : 1) A die is rolled 3 times, let x be the sum of the 3 results . what is var(x) ? I started by calculating E(x)= Segma(1 to 3 (E(Xi)) when Xi is the number we got in every throw . E(Xi)=3.5 then E(x) = 10.5...

Thanks a lot ! very helpful, and good explanation ;)

we roll a fair dice until we get a 6 twice in arrow what is the expectation of numbers of rolls we have to through the dice until we get 6 twice in arrow ? hint : it's not 36 I'll appreciate it if you help me with this question. Thanks