SagarSHAH

i still think its 1/2.....w1 and w2 doesnot make sense to me,,since its clearly mentioned in question the prob to pick a WHITE ball as i already sed.... dnt u have the answer???? lol topgun,,,,u call it easy and u urself make it complicated.....

u knw must be knowing the formula z = (x-m)/sd here,69% of the observations are concerned which coresponds to z = 1. that is observation is in the region +/- 1 Sd.... so substitute values of x,m and z...u get sd as 10... hope my way is correct and its clear,,,,((U may refer to graph from wikipedia,,U knw the link..)

is it 10?? btw the link is not proper,,,

topgun i think second and third possibilities in ur Second soln are same....u have numbered the ball and ias not given in question,,,,they just ask prob to find WHITE ball and not the prob to pick w1 or w2.....

is it 1/2:blush::blush::blush:

can sumone tell me the steps of calculating SD,,,i just wanna know dat in the final step do we divide (sum of squared differences) by 'n' (no of values in set) or we divide by (n-1)...coz in ETS manual it is 'n' and on various sites it is (n-1)....

1) 21--33:hmm: confident abt 2)---it is 96%,,, 3) 16%.......i think now i m rite......

Syed...dude,,,,u Can Avoid Sin Calculations,,,whn U Identified Dat Aoc Is A 30-60-90 Triangle,,,u Knw Its Sides Are In Ratio 1: Root3 : 2.....so No Need To Use Sine-cos Formulas.....they Can Lead To Calculation Mistakes....

Ya,,thanx

It Is Already In Inverse Proportion,,,dats W1 On Rhs And W2 On Lhs...it Works...take Dif Examples And Chk It Out...

Guys A Quick Formula For This Type.. M1*D1*T1*w2 === m2*d2*t2*W1... M--man,,, M1 And m2 D--days,,D1 And d2 T---time ,,T1 And t2 W--work,,W1 And w2.. Substitute Watever Is Given And Ignore Which Is Not Der,,,like Ignore Days In This Example..

thanx suja.....i will do the same....

thanx.. both of u...i really looking forward to increase this thread after my xam( by posting the required things all at one place))... MAY GOD BLESS US ALL....

hey guys,,,i have my GRE is on 20 oct,,,,wat do i do tomorrow??? suggest me??? **THOSE WHO HAVE GIVEN GRE ALREADY WILL HAVE EXTRA TO SAY..... let this thread be for last day revision,,,INCLUDES EVERYTHING DAT IS NEEDED,,math+ verbal.... this cud be useful to ALL of us atleat on the last day...

no prob,,guys,,,,dat sum was from PP,,,verson3.1,,,u will come across it....never mind,,thanx,,,