CT3 questions that are out of scope of CS1 (2013-2018)

Thank you! This saved me a lot of time to help me complete all the 2005~2022 exam questions.

 

Yes, I could identify them now.Thank you.

 

Hi John,
please could you confirm if sept 2012 q 4 is out of scope?

Thanks

 

Sorry, i didnt mean Q4, i meant question 10!

 

great thank you so much!

 

Hi John,

sorry me again, could you double check question 8iv in sept 2018 please? i got caught out on the standard deviation formula, and havent seen this in the course notes

 

also april 2017 question 8 part vii c please?

 

Thank you Andrea, I understand that sd=\sqrt var, i just am having trouble with the logic of how they are obtaining the variance of the multiplied distribtuions

For example
S2017 8vii c
S- total amount on all policies
mean claim amount =100
var of claim amount =20^2

Y- number of claims
E(Y)=195
Var(Y)=308.25

so
E(S)=E(claim amount*Y)=E(meanclaim amount)*E(Y) since indepedent
=100*195 << i undertsand this part

its this part i cant seem to get to an answer for . in my head, we are looking for: Var(S)=Var(claim amount*Y)

the solutions seem to jump to
Var(S)=E(Y)var(mean claim amount)+E(mean claim amount)*var(Y) <<this equation for the variance is the part i dont understand

but where has this equation come from? it seems that this formula for variance is used again in the other question i rasied: S2018 8iv

would really appreciate any help on this.
thanks so much
molly

 

ah, that's a relief that they are out of scope, thank you!