Adam Lucas

21:31

HELLO!

lucyzhang

21:36

HIII

Kaci Gu

21:37

HI

Andrew Huang

21:37

hello

Jesse Thiara

21:38

hello!

lsandoe

21:40

hi

Rebecca Hu

21:41

Hello!

Dorkhan

21:44

hello!

Joshua

21:53

Hi!

lsandoe

22:05

yep

alvin

22:06

Hello There

Joshua

22:09

I miss you Prof. Lucas

lucyzhang

22:11

SAD

Andrew Huang

22:12

yea :/

iPhone (3)

22:14

Miss you too

chelsie

22:17

;((((

lucyzhang

22:21

How is final gonna be done? Do u know yet

Jesse Thiara

22:21

you're an oracle professor

Dorkhan

22:22

sad :(

Joshua

22:43

I don’t like working from home

Adam Lucas

24:27

OHs start today on Zoom. See piazza for details

Adam Lucas

25:53

can you guys hear me

Andrew Huang

25:58

no

Jesse Thiara

26:00

no

brendanco

26:00

no

Kaci Gu

26:01

no

lucyzhang

26:01

no

Joshua

26:04

nope

lucyzhang

26:10

U muted urself I think

Marisol Trejos

26:23

I can’t hear anything

Andrew Huang

26:32

that's good I think

Marisol Trejos

26:49

Yes

Rebecca Hu

26:49

yes

ashley minooka

26:50

ya

Andrew Huang

26:50

yes

ireneyoon

26:50

Yes

brendanco

26:50

yes

Joshua

26:51

yes

Kaci Gu

26:57

yes

Akshara Majjiga

26:57

yes

Andrew Huang

27:29

yes

Joshua

27:29

yep

Jesse Thiara

27:30

yes

brendanco

27:30

ye

Marisol Trejos

27:31

yes

Zachary Zhu

29:33

Yes

lsandoe

30:01

attempted

YeJin Ahn

30:25

working on b rn

Laura Nguyen

31:07

no

YeJin Ahn

31:08

no

ashley minooka

31:08

for b, got no

Joshua

31:09

no

Andrew Huang

31:10

no

iPhone (3)

31:13

No

Marisol Trejos

31:17

no

ashley minooka

31:23

1/3

iPhone (3)

31:23

1/3

lucyzhang

35:24

So the equal sign doesn’t really matter?

Rebecca Hu

36:12

Does k sigma = c?

Joshua

41:43

How did you get 7500?

Harry Xia

42:04

22500-15000

Joshua

42:11

Ah gotcha

Marisol Trejos

42:11

How did you get 5,000?

Zachary Zhu

42:30

Also, wouldn’t Markov give a better lower bound since the probability is lower?

lsandoe

42:38

how did you pick which one is better?

Zachary Zhu

42:39

Oh wait nvm

benskinner

42:40

Why is 4/9 the better lower bound?

Zachary Zhu

42:41

That’s 2/3

Zachary Zhu

42:45

Not 2/5

lsandoe

42:53

ohhhh

Zachary Zhu

42:55

My bad—misread the handwriting

Jessie

43:07

does chebyshev always give a better bound

chelsie

43:08

lol

amywang

43:09

What happened to the absolute value sign around Chebyshev’s? Wouldn’t we have to account for the left tail

Rebecca Hu

43:14

Is there another way to do the Chevyshev?

candice

44:48

Can I do (5000)^2/(22500-15000)^2 for chebyshev?

lucyzhang

44:57

Why did set 7500 equal to k(sigma)

lucyzhang

45:00

u*

candice

45:42

thanks

Harry Xia

45:43

22500 = 15000 + k(sigma)

amywang

45:44

So 4/9 actually represents the probability X is less than 1.5SD and more than 1.5SD from the mean but its just the best we can do to find more than 1.5SD?

carinamassana

45:52

How did 15000+ksigma get to 7500=ksigma

ireneyoon

48:01

^ 22500 = 15000 + 5000k and subtract 15000

brendanco

48:45

Will you be asking for both when testing us?

YeJin Ahn

49:04

I have a question

YT HaliFlame

51:03

How do I raise my hand

ireneyoon

51:29

5 minutes after reading the problem maybe

ashley minooka

53:22

did you mean 1/(k^2)= 1/2?

celine

53:50

^^^^^^

Andrew Huang

53:58

^^^

brendanco

54:21

We’re solving for k

candice

56:14

Can you explain what “p be the proportion of numbers over 5” means

Michelle Sun

57:20

no

Michelle Sun

57:28

oops sorry

Michelle Sun

57:35

accident

candice

57:55

Oh ok got it

Noah Wadhwani

59:14

Wouldn’t it just be > 5? Not >=

Michelle Sun

01:00:26

can we use the logic that because chebychev is for two tails, but because we are only using upper bound it means we have to use markov?

Michelle Sun

01:01:27

yes

Michelle Sun

01:01:32

thank you!

Andrew Huang

01:02:48

on the last question, if we're saying numbers over 4 and we use the p(x>=5) aren't we missing all the numbers between 4 and 5

Alfredo

01:03:10

^^ but I think we are working with discrete values

celine

01:03:14

cheating

YT HaliFlame

01:04:31

lmao

YeJin Ahn

01:06:32

can we solve it by rewriting it as P(|X-u|) >= 30)?

Michelle Sun

01:07:03

why can we take out the square?

candice

01:07:08

How do we know mu is 10?

candice

01:07:13

oh ** sigma

Michelle Sun

01:07:36

yes

candice

01:07:39

Never mind I figured it out

tianyuzhou

01:08:11

Is that 1 - P(|X-u|) >= 30)?

Alfredo

01:08:40

so squarerooting the probability doesn't affect the answer?

Michael Madden

01:09:26

no that is the opposite

Alfredo

01:10:03

but I didn't see 1-(1/9) being squarerooted

Michael navruzyan

01:10:11

why is var(24) = 0

Michael navruzyan

01:10:55

gotcha

Michael navruzyan

01:10:57

thanks

Noah Wadhwani

01:14:18

Where are the recordings of lecture posted?

Michael navruzyan

01:17:13

1

Kaci Gu

01:17:14

1

Sophie Liu

01:17:14

1

YeJin Ahn

01:17:16

1

YT HaliFlame

01:17:17

1

Rebecca Hu

01:17:17

1

Brian Sumali

01:17:57

Do we have to learn how to derive these?

Rebecca Hu

01:18:27

Are we allowed to use the other way for Chevyshev where we do sigma^2 / c^2

Andrew Huang

01:18:32

can you explain where the q comes from again

Brian Sumali

01:18:38

Got it awesome thanks prof

Zachary Zhu

01:18:38

Q = 1-p

Leanna Chraghchian

01:18:46

do you have any info about how our final/quizzes are going to take place??

Brian Sumali

01:18:49

There wouldn’t be any dinner parties soon...

Michael navruzyan

01:19:26

kind of confused on how you can't add those variances in the hours slept example. can't you add var(8) + var(16) = var(24), so 0 + 0 = 0?

Noah Wadhwani

01:20:59

You should just give everyone 100% instead of a final

YeJin Ahn

01:21:05

can you solve the example question part b when rewriting it as P(|X-u|) >= 30)?

Michael navruzyan

01:22:20

yeah makes sense thanks

Alfredo

01:30:12

could you explain the reason why the probability is the same when you take the square root of the probability?

Alfredo

01:30:40

professor?