Category: Probability and Statistics

Question Number 6605 by WAI LIN last updated on 05/Jul/16 $$Letcbeaconstant.UsingVar\left(X\right)=E\left[{(X-E\left[X\right])}^2\right],showthat$$$$\left(a\right)Var\left(cX\right)=c^{2}Var\left(X\right);$$$$\left(b\right)Var(c+X)=Var\left(X\right).$$ Commented by prakash jain last updated…

Question Number 6599 by WAI LIN last updated on 05/Jul/16 $$Provethat\underset{j=1}{\sum ^N}{(X_j-1)}^2=\underset{j=1}{\sum ^N}{X}_j^2-2\underset{j=1}{\sum ^N}{X}_j+N.$$ Answered…

Question Number 6228 by sanusihammed last updated on 19/Jun/16 Terms of Service Privacy Policy Contact: info@tinkutara.com

Question Number 6098 by Rasheed Soomro last updated on 13/Jun/16 $$\mathrm{A}\mathrm{party}\mathrm{of}7\mathrm{members}\mathrm{is}\mathrm{to}\mathrm{be}\mathrm{chosen}$$$$\mathrm{from}\mathrm{a}\mathrm{group}\mathrm{of}6\mathrm{ladies}\mathrm{and}5\mathrm{gents}.$$$$\mathrm{In}\mathrm{how}\mathrm{many}\mathrm{ways}\mathrm{can}\mathrm{the}\mathrm{party}\mathrm{be}$$$$\mathrm{formed}\mathrm{if}\mathrm{it}\mathrm{is}\mathrm{to}\mathrm{contain}$$$$\left(\mathrm{i}\right)\mathrm{exactly}4\mathrm{ladies}$$$$\left(\mathrm{i}\right)\mathrm{at}\mathrm{least}4\mathrm{ladies}$$$$\left(\mathrm{i}\right)\mathrm{at}\mathrm{most}4\mathrm{ladies}?$$…

Question Number 5897 by sanusihammed last updated on 04/Jun/16 $$IffourpeopleallsaidHELLOtoeachotheronce.howmany$$$$timeswouldthewordHELLObespoken?$$ Answered by FilupSmith last updated on 04/Jun/16 $$person1talksto3people$$$${person}\:\mathrm{2}\:{talks}\:{to}\:\mathrm{2}\:{people} \…