BlueGirl18
New Member
- Joined
- Sep 4, 2019
- Messages
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- Gender
- Female
- HSC
- 2021
any help or pointers would be much appreciated! the answer is B, if that helps 
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hard z-score question...any ideas? (1 Viewer)
- Thread starter BlueGirl18
- Start date
Each 
-score is calculated using the formula 
where 
is the student's score, 
is the class average, and 
is the class standard deviation.
So, if you substitute Carol's results, you get that
.
Doing the same for Zachary and Matilda, you will have three equations with only two unknowns. So, you can find what value of and work for two of them, and then figure out for the third whether the problem is an incorrect or and then find the correction that is needed.
So, if you substitute Carol's results, you get that
Doing the same for Zachary and Matilda, you will have three equations with only two unknowns. So, you can find what value of
PS: @BlueGirl18, where is this question from?
BlueGirl18
New Member
- Joined
- Sep 4, 2019
- Messages
- 11
- Gender
- Female
- HSC
- 2021
ahhh... I see! thanks so much!
its from the Killara maths adv trial. I found it on acehsc. I can send it to you?
Thanks for the offer, but I checked and I do have it - I just didn't recognise it and thought it was an unusual / good question.