ECMT1010 - Revision Questions (1 Viewer)

[sarevok]

well..technically not in 'syllabus'...but not in uos outline (at start of blue book)...

 

[myg0t]

recognise, that you are goign to fail

Have you done regression yet avi?

 

[absolution*]

avster:
for any circumstance (less than or greater than)
if t observe>t-critical(if it is positive number) or t observe<t-critical(if it is negative number)
we reject t observe

because in these two condition, the t observe area from the t-diagram is less than the t critical area, we have to reject them.

thats not correct, or at least not explained well. the method you described can only be used when you hypothesis is as follows

Ho: u= x
Hi: u (not equal) x

 

[avster]

abso can you then please explain it better
cheers

 

[stazi]

can someone please help me with a quickie that's easy (if you've done yr 11/12 maths)

(a+b)(c+d)

I seem to remember ages ago having learnt something like this. How do we expand them? Was it something like (a*c)+(a*d)+(b*c)+(b*d)?
and what if it's something like:
(a-b)(c+d)
what happens then?

 

[ToO LaZy ^*]

(a+b)(c+d) = ac + ad + bc +bd

(a-b)(c+d) = ac + ad - bc - bd

 

[s.m.i.t.h]

i still dont get how to do question 57 type linear regression questions
can anyone help!???/

 

[leila]

thats not correct, or at least not explained well. the method you described can only be used when you hypothesis is as follows

Ho: u= x
Hi: u (not equal) x

i just discussed meul < x or meul > x
and the method for reject or not reject is the same in ANY circumstance
if u got a negative number for t observe and positive number for t critical what should u do

i'm pretty sure i'm right

 

[absolution*]

and the method for reject or not reject is the same in ANY circumstance

(1)
Testing H0 : B= B0 against H1 :B< B0
In this case, we reject H0 for large, negative values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the number that satisfies:

We reject H0 if tc < t¤.

(2)
Testing H0 : B = B0 against H1 : B > B0
In this case, we reject H0 for large, positive values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the number that satisifes:

We reject H0 if tc > t¤.

(3)
Testing H0 : B = B0 against H1 : B (notequal)= B0
In this case, we reject H0 for large, absolute values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the positive number that satisifes:

We reject H0 if |tc| > t¤



@s.m.i.t.h what part of qu57?

 

[s.m.i.t.h]

(1)
Testing H0 : B= B0 against H1 :B< B0
In this case, we reject H0 for large, negative values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the number that satisfies:

We reject H0 if tc < t¤.

(2)
Testing H0 : B = B0 against H1 : B > B0
In this case, we reject H0 for large, positive values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the number that satisifes:

We reject H0 if tc > t¤.

(3)
Testing H0 : B = B0 against H1 : B (notequal)= B0
In this case, we reject H0 for large, absolute values of the t-statistic tc.
Using critical value: Let t¤ be critical value.
Then t¤ is the positive number that satisifes:

We reject H0 if |tc| > t¤



@s.m.i.t.h what part of qu57?

question 57 b, c, d

 

[stazi]

hey guys.
remember tig posted lecture notes for continuous random variables. Do we need to know how to do this? It is really bloody confusing. There's strange probability density functions. |'s with little swirly things.
I really can't understand this stuff no matter how hard I try. And i really cant remember being taught this.

 

[ToO LaZy ^*]

im assuming you're talking about those integrals..
i dont really remember him going inot detail with this stuff and it wasnt taught in our workshops..so i guess it PROBABLY wont be examined.

 

[stazi]

im assuming you're talking about those integrals..
i dont really remember him going inot detail with this stuff and it wasnt taught in our workshops..so i guess it PROBABILITY wont be examined.

oh i think it was just an overly complex way of saying here's how to use continuous RV's.
But all you need to know is
Z=x-m/s

 

[stazi]

ok next question:
do we need to know stuff on uniform dist?
It was in the lecture notes, but i dont think we got taught it. Wasn't in the quizzes either. Not sure if its in the revision q's.

 

[absolution*]

ok next question:
do we need to know stuff on uniform dist?
It was in the lecture notes, but i dont think we got taught it. Wasn't in the quizzes either. Not sure if its in the revision q's.

i would know just the basics to be on the safe side. its relatively straight-forward.

my qu.: how do you know when to variables are independent when analysing a probability distribution table.

 

[stazi]

also is question7 doable? we dont have the stdev?

 

[stazi]

i would know just the basics to be on the safe side. its relatively straight-forward.

my qu.: how do you know when to variables are independent when analysing a probability distribution table.

The only condition when two variables are independent are:
P(A|B)=P(A)

or P(B|A)=P(B)

or P(A&B)=P(A)P(B)

 

[absolution*]

qu 7 cannot be assessed - tig.

thanks got that stas

another question: can someone expain or provide info for homo/heteroscedacity and what it all means. will we need to analyse residuals in the exam?

 

[sarevok]

Just going through past quiz possible questions, any one know what the 'modal class' of a histogram is?

 

[absolution*]

Just going through past quiz possible questions, any one know what the 'modal class' of a histogram is?

class with highest frequency id assume

modal derived from "mode"