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MTH 220 May 20 Open Questions
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AvatarGreg Miller
7:28
So, what about X-bar?
Kasey
7:27
2.9814
cool 1
AvatarGreg Miller
That's probably the issue.
7:27
What'd you get for "s"?
Kasey
that's not a good face!
oh no!
7:27
I got t= -9.4922.
sad 1
AvatarGreg Miller
7:26
Yes.. sure
Kasey
?
7:26
ok can I give you what I got for the t value to see if I'm headed down the right direction.
AvatarGreg Miller
7:26
Once we get that right... Ho could be either choice:  equal 20, or greater than or equal 20... no real difference b/t those..
7:25
Yes.. so the focus is on them showing that.. so we need get Ha stated exactly.
Kasey
7:25
ok gotcha this is because in the question we are more concerned with the engines actually being less than 20
AvatarGreg Miller
the key is Ha HAS TO BE exactly right.. and for you it was... so the choice of Ho becomes moot.
7:23
So.. go with whichever one makes the most sense to your interpretation of the language..
7:22
Ok.. then.. IF.. BIG.. IF you have Ha set up correctly, then IT DOESN"T MATTER if you state Ho: mu = 20 or Ho: mu greater than or equal to 20... those two NULL hypotheses are actually the same for the purpose of our problem
Kasey
7:21
yes I got that
AvatarGreg Miller
7:21
Are you good with saying that Ha should be mu < 20.. are you good THERE?
First.. I have to ask you a question before I make my point..
7:20
Ok.. Kasey... here's the thing about situations like this...
7:19
Let me switch out.. I had Firefly up.. give me just a sec...
Kasey
7:19
Hey Dr. Miller!  I chugging right along.  I'm working on the air pollution case. The question makes me want to say that Ho is m greater than equal to 20 but this is just how it reads to me.  Do we still indicate it as m=20?
AvatarGreg Miller
7:14
not a problem... I bet you find it..
Ben
7:14
I'll start on that now. thanks for taking a look into that for me.
AvatarGreg Miller
7:13
if you don't find it.. take a picture and send it to me in email and I can trace all the details after the chat ends...
7:12
So.. go back and check the calculations for s.. b/c somewhere in there, there is a calculation error.
7:11
s = .3027
Ben
7:11
S ended up being 0.9905
AvatarGreg Miller
7:11
that's the error..
7:10
ok... must be a calculation error... let's trace it.. probably your value of "s" isn't correct... what'd you get for s?
Ben
7:08
then multiplied it by 2
AvatarGreg Miller
7:08
OK.. let me check something... hold on.. this may take a bit
Ben
7:08
My t-statistic turned out to be -0.8884 (that is a negative). I took the absolute value of this to calculate the p-value.
AvatarGreg Miller
7:06
What'd you get for the t-statistic?  admittedly.. I don't have my key with me
7:05
OK..  I had to erase my original comment..
Ben
7:05
that should be an approximate sign, not a negative
7:04
Hi Dr. Miller. I did the firefly homework assignment and had a couple questions. First, is this a 2 sided hypothesis test, and if so, does a p-value of ~0.39 seem reasonable?
AvatarGreg Miller
6:58
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