ECMT quiz 2 (1 Viewer)

[absolution*]

i used st dev of 5 in all of b, so they will be wrong

 

[Lainee]

Furthermore, could someone explain q3.a.
My logic is a bit off.

How do we find the probability of him arriving after 8:30, based on him leaving at 8:00?
I understand if it was just P(X>8:30)
Although, I'm not even sure if that would be correct as minutes an hours only have 60 and 24 units. This could lead to incorrect calculations.

It would be P(X>30). X refers to 'driving time' so it doesn't matter that he left home at 8.00, what matters is whether driving time would exceed 30 minutes.

 

[Lainee]

For Q2(b) I had different answers to the ones 1time posted. I got a=1 and b=99 by saying:
a=(-1.96)25 + 50
b=(1.96)25 - 50

The difference between our working out is that I substituted the Z values as 1.96 and -1.96.



Hmm... are we meant to use the tables from our textbook or the ones at the back of our workshop booklet?

 

[jpr333]

Use your text book, they are more accurate.

 

[Rorix]

sorry re: my previous post, got the questions confused, 3b is simultaneous equations

 

[matt#1]

You guys have done so much work already...I only just looked at the questions this afternoon. I will try to help with the answers if i am able to do the questions.

 

[stazi]

For Q2(b) I had different answers to the ones 1time posted. I got a=1 and b=99 by saying:
a=(-1.96)25 + 50
b=(1.96)25 - 50

The difference between our working out is that I substituted the Z values as 1.96 and -1.96.



Hmm... are we meant to use the tables from our textbook or the ones at the back of our workshop booklet?

I think we only get the ones at the back of the blue book
And youre correct. I put in the probabilities, not the Z values

 

[stazi]

Could someone please provide working for 3b. I am really unsure about how simultaneous equations are done. Did we get taught this?

 

[absolution*]

Re: 3(b) I got the equations and tried all simultaneous eqn methods i could think of but i couldnt solve the equations to find a reasonable solution.

 

[sarevok]

can you post how you got the equations plz?

 

[absolution*]

How do we find the probability of him arriving after 8:30, based on him leaving at 8:00?
I understand if it was just P(X>8:30)
Although, I'm not even sure if that would be correct as minutes an hours only have 60 and 24 units. This could lead to incorrect calculations.

HAha stasmo. Youre such a silly poo,

 

[absolution*]

can you post how you got the equations plz?

Got crabs so i cant get up. Im sure someone else will post them up.

 

[stazi]

sarevok - which equeertions?

 

[absolution*]

Use your deductive reasoning powah's!

[3 (b) - the eqns which you are meant to solve simul to get your answer]

 

[sarevok]

nm, worked out how to get them

 

[stazi]

I hate maths. I hate not doing it in yr 11 or 12. I just need to pass this course. Then i can do tig.

 

[ToO LaZy ^*]

hey stas..i checked your answer for 2d)..and i was wondering..why did you calculate the standard error?

 

[stazi]

hey stas..i checked your answer for 2d)..and i was wondering..why did you calculate the standard error?

I was under the impression that sampling distribution is calculated with the standard error.

 

[ToO LaZy ^*]

hmm..but you've got sigma as the mean (50) instead of 25....?

 

[stazi]

in that case i lose. Damn it. I hate metrics.