Alex xi

21:34

yes

Sophie

21:35

yes!

joel chang

21:35

yep

Kaci Gu

21:36

yes

joel chang

22:02

Thank you

Laura Nguyen

23:22

it’s a lot

Jooee Karwande

23:36

Material makes sense

isaacecheto

23:43

It’s making sense though

YeJin Ahn

23:51

makes sense but dense

celinewherritt

23:59

Can be kinda confusing

Alex xi

24:05

yes

celinewherritt

24:09

Yes like A/B testing

mayareuven

24:12

yes

isaacecheto

27:35

Reject null

YeJin Ahn

27:36

reject

celinewherritt

27:38

Reject null , its above

michellecan

27:38

reject

Zachary Zhu

27:38

reject

Kieran Cottrell

27:42

reject

Matthew Simon

31:14

In the above example, how did you get the population standard deviation to be .7? Wasn’t .7 the standard deviation of one sample of size 100?

Kaci Gu

32:14

this is a qn about the warm-up problem too. Is the confidence interval open or closed?

amywang

34:20

What’s the difference between x bar and mu?

Michael Madden

36:50

maui beast!!

Micah Grim

37:13

Good question Matthew

amywang

37:24

yes

amywang

37:27

Thank you

Matthew Simon

38:34

Thank you michaels

Laura Nguyen

41:17

can you clarify what it means when you say we’re each making 95% CIs

Joshua Kim

41:51

Is this saying 95% of us will have the correct CI?

Laura Nguyen

42:28

yes thanks

Joshua Kim

42:59

ok

Joshua Kim

43:01

yes

Noah Wadhwani

43:26

No

Forrest Kim

43:26

No

Matthew Simon

43:30

No

Natalie

43:32

no

mayareuven

43:33

No

Rebecca Hu

43:34

no

parkersalomon

43:40

no

YeJin Ahn

43:45

100

Jooee Karwande

44:05

no either it con

Zachary Zhu

45:31

So just to clarify, does that mean that we cannot assign probability once an interval is fixed?

Zachary Zhu

46:18

Thank you

Michael Madden

48:04

when was this sample taken

louisnorris

50:00

Is that the same thing as saying 95% of all the samples will fall in the range we found?

louisnorris

51:19

okay thank you

amywang

51:22

Is this saying that 95% of samples of this size from the population will contain CI’s with mu?

michellecan

52:08

Resample from the sample

Andrew

52:16

sample the sample with replacement

Michael Madden

52:25

do this process over and over from the pop

Michael Madden

52:42

1174?

Joshua Kim

52:45

Whatever the sample size of the sample is

Michael navruzyan

56:20

does CLT apply on the resampled with replacement samples?

Dorkhan Chang

59:09

how do we bootstrap without python on a quiz/final

Michael navruzyan

01:00:48

thanks

Joshua Kim

01:05:19

Isn’t it 2sigma/sqrt(n)?

Rebecca Hu

01:05:33

Is sigma the sd for the population or the sample?

Claire MccCallick

01:05:39

yes

Jingyu Han

01:05:44

Yes

Jooee Karwande

01:05:53

yes

parkersalomon

01:05:54

no

YeJin Ahn

01:05:55

no

Zachary Zhu

01:05:56

No

Justin Im

01:05:58

no

Forrest Kim

01:06:02

no

Micah Grim

01:06:09

Absolutely not

Matthew Simon

01:06:57

Can you please repeat what 5.8 is the standard deviation of?

Forrest Kim

01:07:29

What is the significance of the bounds of a confidence interval?

Joshua Kim

01:07:45

So there is a 95% chance that the population mean is contained within that interval?

Matthew Simon

01:09:20

Is 5.8 an approximation based on the sample, though?

isaacecheto

01:10:53

city

Rebecca Hu

01:10:55

City

celinewherritt

01:12:19

income

Michael navruzyan

01:13:31

could you explain how it is "all possible" simple random samples

celinewherritt

01:13:36

false

michellecan

01:13:37

false

Kaci Gu

01:14:06

Thank you

mayareuven

01:14:06

thank you!

louisnorris

01:14:10

thanks!

Joshua Kim

01:14:11

Thanks

lucyzhang

01:14:14

Can u repeat all the reasonings behind last Q pls

isaacecheto

01:14:16

Thanks prof

Jingyu Han

01:14:17

Thank you!

Micah Grim

01:14:19

Thanks uncle adam

Claire MccCallick

01:14:19

Can you explain why C is false?

Tanvee Joshi

01:14:22

Thank you!

lucyzhang

01:16:20

Can u repeat all the reasonings behind last Q plsFrom isaacecheto to Everyone: (03:01 PM)
4000 is from SD of sample not city?

Claire MccCallick

01:16:33

I think it might be a typo?

lucyzhang

01:16:38

Wait 4000 sorry nvm

Rebecca Hu

01:16:46

4000 is the 2sd / root n

Michael navruzyan

01:18:04

can you please go over why its the averages of all possible simple random samples again?

Matthew Simon

01:18:22

So is the standard deviation of 40,000 an approximation of the city’s SD based on what we got in a large sample?

Claire MccCallick

01:18:44

Okay, thank you!

Claire MccCallick

01:18:49

yes

Claire MccCallick

01:18:53

Much better

sophia

01:19:00

So the CI is for the sample?

lucyzhang

01:19:08

Can u go over a and b also pls

sophia

01:22:54

why 40000 not 4000 for part d?

lucyzhang

01:25:03

Is it frozen or just me? Sorry

YeJin Ahn

01:25:05

can’t hear you professor

lucyzhang

01:25:16

^^

sophia

01:25:19

^^^

Adam Lucas

01:25:36

can’t hear me? hold on

lucyzhang

01:25:47

Okay! Thx

Matthew Simon

01:26:14

I’m still confused on how we get the the population’s standard deviation to be 40,000. We aren’t explicitly told this, but rather are told that the standard deviation of one sample of size 400 is 40,000. But then in calculating the standard deviation of the sample distribution, we use 40,000 for the population standard deviation. Could you please explain this?

lucyzhang

01:26:22

^^

sophia

01:27:02

yes

Matthew Simon

01:27:02

Yes

YeJin Ahn

01:27:04

yes

sophia

01:28:20

so 40000 is the sample SD?

sophia

01:34:48

For C, would it be true if we change “in the city” to “in the sample”?

Matthew Simon

01:38:29

Thanks again!

Adam Lucas

01:38:51

hold on!

lucyzhang

01:39:15

Ok! Thx

YeJin Ahn

01:39:16

Thank you professor!!

lucyzhang

01:42:18

Thank you Prof!