for 7i i left the answer of the sum of w^2 in exact form not 3sf as we needed it for later results. Do you think I'll lose a mark? Also for the last question 9ii I did 10C5 x 0.2^5 x 0.8^5 and got 0.2646 did anyone else??

Reply 12

haarithiop

11

Original post by Amrit599

for 7i i left the answer of the sum of w^2 in exact form not 3sf as we needed it for later results. Do you think I'll lose a mark? Also for the last question 9ii I did 10C5 x 0.2^5 x 0.8^5 and got 0.2646 did anyone else??

you won't lose a mark for exact form

Reply 13

Luca715

9

for 6 iii i multiplied by 2 to get 1/15 because there are 2 judges so the same can happen again the other way around, i dont get why this is wrong can someone please explain??

(edited 6 years ago)

Reply 14

Billy_Boi

10

If I figured out mean and standard deviation of the x values instead of the x and w values do you think I'll lose all marks?

Reply 15

username3179140

OP

9

Original post by Luca715

for 6 iii i multiplied by 2 to get 1/15 because there are 2 judges so the same can happen again the other way around, i dont get why this is wrong can someone please explain??

Hi for that questions the probability of all 5 ranks matching is 1/5 * 1/4 * 1/3* 1/2
which is 1/120 however either judge can get this so *2 1/60

The same applies for the other judge = 1/120 however there are two judge so either one of them so 1/120 * 2 = 1/60

then 1/60 + 1/60 = 2/60 = 1/30 thats how i got that answer of 1/30