ECMT Quiz 3 (2 Viewers)

[WaffenssLAH1985]

In q2 (b), the testing requires LOS, r we supposed to set LOS by ourselves because there is no LOS provided?undefined

 

[sarevok]

yep. the p value is virtually zero, so whatever los you choose it's likely to be rejected anyway.

 

[Lainee]

this is murray's answer to one of those find the probability of a type b error questions

i believe this is question e)

i don't understand his working, so if some one smart i.e. lainee can explain it that would be good (sorry for shitty mspaint but scanner is broken)

and yes, there is a typo with brackets

edit: also, the upper crit value equals 163

What I don't understand here is why it turns into a Z in the last two lines... shouldn't it be a t?

2.in q 1(d), my p-value is p(Z>1)=1-0.8413=0.1587
3.q 1(e), my p is p(absolute Z>0.73)=0.2327*2=0.4654
4.in (f), mine is Ho=80, H1>80, tobs is 1.22, the p-value isp(Z>1.22)=1-0.8888=0.1112

Same problem here with p-value. Aren't we working with sigma unknown here? Therefore, using t-statistic not Z? Again, I'm working off slide 37 from Murray's lecture notes.

 

[sarevok]

when can the t distribution be approx. from the z tables? when n>100??

 

[WaffenssLAH1985]

we canreceive approx value of p by putting t value into Z table

 

[s.m.i.t.h]

in the ANOVA table how do u work out A and B???

 

[s.m.i.t.h]

whoops dumb question
i figured it out

 

[avster]

for parts of question 1) as 1 time didnt know as well

how do you work out the probability of a type 2 error? for example in question 1d part iii)

cheers

 

[jpr333]

Our tutor has said you will basically never be asked that as he doesn't even know and it took a 4th year London stats book for a girl in my tute to figure it out.

Ps had this today had the km's hypoth qs and parts of what appeared to be q1 of the linear regression q's plus interpretation.

 

[04er]

for the first question, did anyone reject the manufacturer's claim that average life > 50 000 ??

 

[04er]

For this question, I would have taken a completely different approach.

(Not a complete solution, but just highlighting some differences in approach in my solution and yours.)

Ho: u=90
H1: u<90

At 0.05 level of significance, reject Ho if t<-1.6604

Calculating test statistic using t-statistic:
t=-2

Since t<t(critical) reject Ho at 5% level of significance and conclude that average amount spent per household per week is significantly less than 90.

Why is the critical value of t a negative? I know that's right but I'm not sure why (it is because of H1: u<90?)

 

[stazi]

for the first question, did anyone reject the manufacturer's claim that average life > 50 000 ??

hey is a guy called Henry in your class. Asian punker. Droopy hair.

 

[stazi]

yes. i win the quiz.
We had one really tricky question, however I think I got it right. Because im smart.
We had the wine vs heart disease question without the scatter plot chart attached.
The question was the:
"what will be the heart disease statistic for the average australian wine consumption of 2.4L. The real one is X. What is the residual?"
I used the y intercept or whatever its called (the first one on the left of the second excel table given) and subtracted 2.4 x 26 from it. Then i quoted that as the average aus statistic from the sample. and said the residual is the 'real mean'-'sample mean'
Some really smart guy got the same answer as me

Stas, the non-year11/12 maths guy is going to win econometrics.
Oh and if i get a credit, im buying 4 jugs for everyone at manning.

 

[04er]

hey is a guy called Henry in your class. Asian punker. Droopy hair.

i dont think so... (btw my name isn't Henry. I'm not asian. I'm not a punker. And I don't have droopy hair. If that's what you're implying )

 

[stazi]

i dont think so... (btw my name isn't Henry. I'm not asian. I'm not a punker. And I don't have droopy hair. If that's what you're implying )

no. im implying he's a mate of mine. and he got the same question as you. and grace thinks he's hot.
So in a roundabout way - are you attracted to him?

 

[sarevok]

Damn, the people in the Thursday tutes always seem to get the easy questions.

 

[04er]

no. im implying he's a mate of mine. and he got the same question as you. and grace thinks he's hot.
So in a roundabout way - are you attracted to him?

haha my quiz is tomorrow.
And fortunately I'm not gay. (no discrimination intended)
So no, I'm not attracted to him. Are you?

 

[absolution*]

Stas, the non-year11/12 maths guy is going to win econometrics.

You better hope so since you obviously suck at everything else in life except studying really hard for mediocre grades.

 

[stazi]

You better hope so since you obviously suck at everything else in life except studying really hard for mediocre grades.

its true. oh well, everyone has their talents. like you. sucking balls.

 

[kow_dude]

Easy peoples, let's keep the peace here....