statistic help...

[AuTh3nTiK]

I really need help with this question: nov 09 paper 61
http://www.xtremepapers.net/CIE/ind...l/9709 - Mathematics/&file=9709_w09_qp_61.pdf

Can anybody help me with ques no 3 second part...

thanks in advance

 

[Xenon]

for this part, u will need to find the time below which journey times are considered short and the time above which they are considered long. The two time will give u the least and greatest time for standard journeys.

to find the least time, considering X to be time taken for any journey and L be the least time,
P(X>L)=0.33 (the % of short journeys)

for greatest time, considering M to be the greatest time,
P(X<M)=0.33 (the % of long journeys)

Solve for L and M. The least time is L and M is the greatest time for standard journeys.