Ocr mei statistics 1 exam thread (24/05/13)

I think it was because there were 9/200 that had a weight heavier than the highest females weight, so 9/200 * 8/199 as you needed to pick two

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Nope sorry thats wrong because it said if she hits one in the first 3 throws then she just stops

so

BBB NNNBBB
if it was BNNBBN she'd just stop after BNN

No it was if she hit bulls eye in at least 1 of her 3 throws she will not throw her next 3. So it was asking what was the chance of her hitting 3 bulls eyes

So it was:
Hitting 3 bulls eyes in the first 3 throws + hitting 3 bulls eyes in the last 3 throws given that she hit no bulls eyes in the first 3 throws.

how did you calculate the iqr? Did you add 1 or leave it at 25 before calculating the quartiles?

how did you calculate the iqr? Did you add 1 or leave it at 25 before calculating the quartiles?

What would I get out of 18 if I did everything right, and had the correct method etc, but I read the data wrong and therefore did the probability tree wrong. As I then used the probabilities from the tree, I then used the wrong probabilities throughout.

Would I lose one mark for accuracy on just the tree diagram and get follow through on all the others or would I lose 1 mark per question?

Also, I think the boundaries will be pretty high. 59 for an A, 52 for a B, 45 for a C.

For which question, if it was the data set i just did n+1/2 for the mean then just halfed that number for LQ and added 6.5 on for the HQ from the mean. For the cumulative frequency I just did 100th value for median 50th for LQ and 150th for UQ

for the 2nd question first part
it was like 5 men and 5 women 2 womens win the prizes and 1 man wins the prizes find the probability this happens.
So i did 5/10 x 4/9 x 5/8 x 3!

is this correct...or will it get me a mark or two... it did say simply ur answer which i couldn't so deffentaly something wrong

i expect so, i think it was an easy paper in general and many people i spoke to had lots of time left to spare

For which question, if it was the data set i just did n+1/2 for the mean then just halfed that number for LQ and added 6.5 on for the HQ from the mean. For the cumulative frequency I just did 100th value for median 50th for LQ and 150th for UQ

would you lose marks if you did just 0.75or 0.25 times 25 instead of 26 because i checked both and they gave different upper and lower quartiles but the same iqr