Logo

SOC 3811/5811: Synchronous Class - Shared screen with speaker view
Julia Grove
20:07
I got 0 on one of my trials but that isn't an option
MacKenzie Lenhart
20:40
I also had no face cards or aces but can’t choose 0 as an option
Brooklyn A Duffy
21:17
I just used 1 instead
John R Warren
28:25
https://docs.google.com/presentation/d/1oGDIWjqPKfqo1qZdte0rWNSdM26PVd6Kvxb6vgoLvo4/edit?usp=sharing
Timothy S Opdahl
34:58
83.84%
Samantha Thomas
35:00
Can you work through it also
Alex M Wells
35:09
^
Carly Wolff
35:13
^
Hayat Muse
35:14
^
Kyle Theisen
35:16
^
Sovahn Yong
35:26
^^^
Ryan A Moon
35:27
Havent calculated but z score between 0.03 and 0.04
Elizabeth A Zanmiller
35:29
ok I think we are good on the arrows guys
Sovahn Yong
35:34
^
Kathryn M Meenan
35:51
we didn’t feel like we had enough time or all understood it
Neeraj Rajasekar
35:55
ROFL. We have fun in here
Linda Lubi
36:55
is there a specific chart that we have to look at for z-scores?
Twisha A Boradia
37:05
Can you go back a slide
Eliza G Scholl
37:13
could you slow down a little please?
Elise Cook
37:15
There is a chart on the course site
Lucija L Magurs
37:15
^^^
De Andre T Beadle
37:31
Yes see the course webpage for Z table
Kayla T Truong
37:32
The equation
MacKenzie Lenhart
37:33
The z-score sheet is on the class website so u can find them!!
Ashley Ochoa
38:10
so you basically subtract the zscores?
Idiris Ali
38:36
How did he get (.85)?
Eliza M Lombardy
38:48
Why did I get .14 instead of 1.4?
Timothy S Opdahl
38:50
1-p-hat
Neeraj Rajasekar
39:16
You probably did root() without the /100 [check ur denominator]
Caitlin M Boucha
39:23
1-0.15 = 0.85
Idiris Ali
39:32
thxs
Carly Wolff
39:33
How do u get 0.9192 and 0.0808
Ashley Ochoa
39:44
^^^
Elizabeth A Zanmiller
39:50
those are the scores on the z chart I believe
Elizabeth A Zanmiller
40:26
like the area that corresponds with the 2 z scores he found
Elizabeth A Zanmiller
40:32
(maybe lol)
Neeraj Rajasekar
40:47
Elizabeth is correct
Neeraj Rajasekar
40:58
Those will correspond to areas
Elizabeth A Zanmiller
41:01
aye
Carly Wolff
41:11
Can he go through that
Kyle Theisen
42:18
PLEASE
Elizabeth Kulig
42:24
^
Claire L Laudi
42:49
Sorry so what is the formula? Do you use p hat - p for the numerator
Claire L Laudi
42:54
Or just the bottom
Neeraj Rajasekar
43:36
Claire, you use that twice. P hat = .15, p1 = 1-, p2 = 20
Neeraj Rajasekar
43:50
but the denominator (st error) is same each time
Kayla T Truong
44:02
yes
Hayat Muse
44:03
Yes
ender106@umn.edu
44:28
Z table: https://www.rob-warren.com/uploads/4/5/1/2/45120697/z_table.pdf
Emma C Kopet
45:24
So you convert Z score into the table for both and subtract the small z score value from the larger one to find the area under the curve between the two points
Neeraj Rajasekar
46:10
More or less correct. We'll go thru it
Hayat Muse
47:30
The way I see it is if you ignore the Z-score aspect of this and you were just trying to find out the numbers between 1 and -1 you’d subtract 1 from -1 getting two so if you ignore the fact that you’re subtracting z scores it’s basic algebra.
Idman Adan
47:58
Subtracting the two leaves you with what is in between
Neeraj Rajasekar
48:09
That's true, but don't neglect the importance of the Z score. And I wouldn't bank on that, it won't work every time (negative vs positive numbers)
Kathryn M Meenan
52:34
so for the worksheet it is P(Z greater than 1.4) - P(Z less than -1.4)= .9192 - .0808
Ella Farley
53:09
yes
Claire L Laudi
53:11
Yes
Neeraj Rajasekar
53:13
The math is right, but both are technically Z < 1.4
Neeraj Rajasekar
53:27
the word "Greater than" is a small mistake. It always reports Z < X
Kathryn M Meenan
53:44
thanks!
Ryan A Moon
56:31
in question 6 on the worksheet, it notes the standard deviation. Is this something we do not worry about in the equation this it’s not a factor?
Neeraj Rajasekar
56:44
S = st dev. You need S to calculate SE
Ryan A Moon
56:46
since*
Neeraj Rajasekar
56:48
SE = st error
Elise Cook
59:05
will the SD always be the same just one pos and one neg?
Madelyn L Wolf
59:50
Isn’t the mean the second number in the numerator for z scores?
Kyli R Nault
01:00:17
Don’t we use the t table for mean?
Asiya N Browne
01:00:25
@elise no for example for the cat question he could’ve asked between 10 and 25% in stead of 10 and 20 and then they wouldn’t be the same
Elise Cook
01:00:38
Ok that’s what I thought
Hannah Hagen
01:00:52
I thought t table was only for small samples under 50?
Kyli R Nault
01:01:07
ya its a sample of 40
Elise Cook
01:01:17
he said we would always use t scores from now on, we just haven’t gone over them yet
ender106@umn.edu
01:01:45
I think t scores can be used for small and big samples, z scores should only be used for big samples?
Kyli R Nault
01:01:55
This doesn’t make sense
Eva M Arago
01:02:23
So yeah he should’ve used the t-table ??
Elise Cook
01:02:25
T scores can be used all the time, but you will be less accurate if you use z scores for a smaller means
Julia Grove
01:02:33
t scores are used for small samples because they give you a margin of error
Julia Grove
01:02:45
z scores are accurate only with large samples
Elise Cook
01:02:50
he said in the recorded lecture we will just use t scores after today because you will always be accurate unlike z scores
Neeraj Rajasekar
01:03:17
The math is mostly the same too, btw.
Neeraj Rajasekar
01:03:26
Just the numbers in the tables
Dylan G Brown
01:13:58
Yep
Peach Schmidtlein
01:29:33
So would the final answer to this question be >0.999 ?
Neeraj Rajasekar
01:30:01
Technically, rob has written "greater than or equal to .99," but yes that's fine
Zaynab A Somani
01:30:09
Where does the 0.999 come from? Is that the final answer?
Neeraj Rajasekar
01:30:15
1- .0001 ish
Neeraj Rajasekar
01:30:36
technically, 1 - (.001 * 2) ish
Claire L Laudi
01:31:00
What about .0005 x 2
Zaynab A Somani
01:31:05
Oh ok thank you
Ryan A Moon
01:31:09
That works
Sarah L Davis
01:31:21
I have the same question as claire
Neeraj Rajasekar
01:31:24
"ish" is a very subjective concept. the general point is NEARLY ALL ppl go to the bathroom in that 3. 9 - 5.1 window
Flora Yang
01:31:27
@claire you take the 0.01 to be more conservative because it is larger
Ryan A Moon
01:31:29
claire you’re right
Neeraj Rajasekar
01:31:48
in tests, etc. we won't leave you with imprecise numbers. but yeah .005 * 2 is valid
Ida Ky
01:32:49
#1 on the WS wasn’t on the recorded lecture