00:09:57 Ekua-Yaaba Monkah: Long week! 00:10:04 Anai Ramos: Good! A lot of hw 00:10:06 Silvana Larrea: Hi, good :) 00:10:15 Julia Hankin: Doing okay! Lots going on, Epi midterm on Monday 00:10:22 Nikki Marucut: How are you doing? 00:10:55 Nikki Marucut: Is that phn250A? 00:11:04 Cristal Escamilla: yes 00:11:06 Nikki Marucut: That y’all are talking about 00:11:09 Nikki Marucut: GOOD LUCK 00:11:21 Cristal Escamilla: Thank you! 00:11:27 Nikki Marucut: I took it in the summer, it’s hard 00:11:31 Nikki Marucut: And I feel for yall 00:11:35 Nikki Marucut: You got this! 00:14:21 Nikki Marucut: Are we going to get access to these slides? 00:18:03 Nikki Marucut: Thank you! 00:20:03 Ijeoma Uche: The last 10 .. z-score and on 00:20:09 Laura Sanavio: Question 2 00:20:39 Annalisa Watson (she/her): #10 & 11, then zscore and on 00:20:51 Arianna Libenson: 3 00:21:10 Ijeoma Uche: #9 00:21:16 Michele Ko (she/her): Agree with z score and on 00:21:24 Ijeoma Uche: #11 00:21:27 Nikki Marucut: Question 8 and 9 00:21:37 Ijeoma Uche: #14 00:21:43 Julia Hankin: Just to make sure I understand, for Part 1 we aren’t using any R functions to calculate, correct? Just using R functions for Part 2? 00:22:29 Ijeoma Uche: #2, #9, #11, #14, and the last 10 (z-score and on) 00:23:52 Kelsey MacCuish: @Julia right! there’s some math for the first part, but the code really comes in in the last part 00:24:02 Kelsey MacCuish: (and also with uploading your tree diagram) 00:24:06 Kelsey MacCuish: (in the screening part) 00:25:14 Aliza Adler: I’d vote for going over probability and then z score s(differences between pnorm, qnorm, and rnorm) 00:25:42 Ekua-Yaaba Monkah: #6, #9, Normal Distribution, and Z score questions 00:26:18 Lian Hsiao: Can we go over a bit of every part so we get an idea of how everything looks 00:26:46 Silvana Larrea: If possible I would like to review 5,6 and 7 :) 00:26:54 Kelsey MacCuish: yes we definitely will go over at least a little of every part! Just wanted to know where to start bc we didn’t get to spend as much time on normal dist in my other lab 00:27:38 Ijeoma Uche: Is it possible to access the recordings to the other lab? 00:27:59 Annalisa Watson (she/her): I think only this lab section is recorded^ 00:28:51 Laura Sanavio: When is the recording usually posted? I will not be able to stay the full time because I have another class after 00:31:16 Mariah Jiles (she/her): above the mean? right side of graph 00:31:17 Hiruni Jayasekera (she/her): between 0 and 1 00:31:19 Taylor Yoo: to the right of the mean 00:31:25 Nikki Marucut: It’s about 2-2.5 away from the mean? 00:33:57 Aliza Adler: Doesn’t it say it differently in the lab though - it says qnorm you input a probability? 00:34:21 Nani Conklin (she/her): same question - I have in my notes that we use pnorm to find the probability of a point on the curve 00:35:03 Hiruni Jayasekera (she/her): the notes say pnorm() uses the value of x and calculates the probability below that point 00:36:45 Phoenix Ding: I think qnorm is given probability area, while pnorm is to calculate probability area 00:37:08 Aliza Adler: ^that tracks with my notes on pnorm from class too 00:39:16 Nani Conklin (she/her): we haven't actually learned qnorm in class yet :/ here's the explanation of pnorm from the lecture yesterday: 00:39:37 Nani Conklin (she/her): pnorm(q = 1.2, mean = 0, sd = 2), to calculate the cumulative probability below a given value 00:42:11 Nani Conklin (she/her): yes! thank you :) 00:42:13 Taylor Yoo: yes :) 00:43:13 Hiruni Jayasekera (she/her): i’m getting an error after inputting this code: p15 <- qnorm(q=0.8, mean = 0, sd = 1) 00:43:16 Hiruni Jayasekera (she/her): Error in qnorm(q = 0.8, mean = 0, sd = 1) : unused argument (q = 0.8) 00:43:25 Hiruni Jayasekera (she/her): anyone else having this problem? 00:43:50 Alexis O'Connor: you have to add lower.tail=TRUE, log.p=FALSE 00:43:51 Hiruni Jayasekera (she/her): whoops i figured it out 00:44:04 Aliza Adler: ^yeah, I had to remove q = and just enter .8 00:44:15 Hiruni Jayasekera (she/her): thanks aliza! 00:44:27 Phoenix Ding: Can you try qnorm(p=0.8)? 00:46:33 Hiruni Jayasekera (she/her): i figured it out! i did p = 0.8 00:47:11 Annalisa Watson (she/her): qnorm 00:47:14 Hiruni Jayasekera (she/her): qnorm 00:47:44 Mariah Jiles (she/her): lower tail= FALSE 00:47:45 Ala Koreitem: lower.tail = F 00:49:47 Hiruni Jayasekera (she/her): pnorm? 00:49:53 Aliza Adler: Qnorm 00:49:54 Mariah Jiles (she/her): qnorm 00:49:58 Ekua-Yaaba Monkah: qnorm 00:50:32 Michele Ko (she/her): 3350 00:50:37 Nani Conklin (she/her): use qnorm to find the z score with a probability of 0.25 and use the mean of 3350 and sd 440 00:51:40 Annalisa Watson (she/her): qnorm(.90, mean=3350, sd=440) 00:51:41 Hiruni Jayasekera (she/her): qnorm 00:51:43 Ekua-Yaaba Monkah: qnorm 00:52:51 Julia Hankin: Norm? 00:52:51 Lupita Ambriz: pnorm 00:52:52 Aliza Adler: Qnorm 00:53:19 Annalisa Watson (she/her): 75th-25th 00:55:17 Chitra Nambiar: lB <- qnorm(0.25,mean = 3350, sd = 440 ) uB <- qnorm(0.75,mean = 3350, sd = 440 ) p19 <- c(lB, uB) 00:55:21 Silvana Larrea: c(qnorm (0.25, mean = 3350, sd = 440), qnorm (0.75, mean = 3350, sd = 440)) 00:57:18 Aliza Adler: Pnorm since we want probability 00:58:17 Phoenix Ding: 55,mean=50,sd=5,lower.tail = FALSE 01:00:02 Nikki Marucut: i 01:00:07 Nikki Marucut: I’m glad we’re going over this 01:00:09 Nikki Marucut: LOL 01:00:17 Nikki Marucut: It’s so confusing 01:00:26 Mariah Jiles (she/her): ^^^ 01:00:30 Ekua-Yaaba Monkah: im confused lol 01:00:48 Mariah Jiles (she/her): I personally would like to start from the start 01:00:53 Ekua-Yaaba Monkah: yea I agree 01:01:19 Nani Conklin (she/her): could you please post the round function in the chat? do we need to know how to use that? 01:02:22 Aliza Adler: I’d also like to go over #21 at some point if possible- struggling with the examples where we take two given bounds/probabilities 01:02:23 Cristal Escamilla: I got 100 for p20...round(pnorm(0.55, mean=50, sd=5, lower.tail = FALSE)*100, 2) 01:02:53 Cristal Escamilla: got it thank you! 01:03:26 Nani Conklin (she/her): Mariah, did you mean start at the beginning of the normal dist work or the beginning of the lab? 01:03:48 Mariah Jiles (she/her): whoops I meant start at the beginning of the lab 01:03:52 Nani Conklin (she/her): I assumed you meant the latter but that might've been me projecting, since I'd like to start from the beginning of the lab! 01:03:59 Mariah Jiles (she/her): thanks for clarifying Nani 01:04:17 Max Billat (any pronouns): can we go over #15 please 01:04:22 Annalisa Watson (she/her): Can we go over #11 01:04:49 Aliza Adler: I’d still like to go over #21 please 01:04:51 Michele Ko (she/her): Can we finish normal distribution though 01:04:59 Ala Koreitem: Can we go over #21 01:05:09 Nikki Marucut: ^ala 01:07:32 Christopher Patterson: pnorm(55, mean = 50, sd = 5) 01:08:04 Aliza Adler: pnorm(q = 40, mean = 50, sd = 5) 01:09:13 Ijeoma Uche: Im getting errors 01:09:17 Cristal Escamilla: me too 01:09:17 Mariah Jiles (she/her): same 01:09:18 Yulan Xie: ^ 01:10:07 Kelsey MacCuish: round((pnorm(55, mean = 50, sd = 5) - pnorm(40, mean = 50, sd = 5))*100, 2) 01:10:09 Nani Conklin (she/her): Thanks, Kelsey! I have to head to another class now - do you know when the recording will be posted? 01:10:57 Nani Conklin (she/her): super :) i'll check it out tonight, thanks! 01:11:01 Jessica Fields (she/her/hers): Yes I want to go over #3!! 01:11:05 Nikki Marucut: I do too 01:11:05 Arianna Libenson: I said #3! haha 01:11:06 Olufunke Fasawe: Let 01:11:12 Hiruni Jayasekera (she/her): also #2…haha 01:11:14 Olufunke Fasawe: Let's start from the begining 01:12:29 Olufunke Fasawe: 0.35 + 0.5? 01:12:30 Annalisa Watson (she/her): .35*.45 01:12:30 Hiruni Jayasekera (she/her): multiply the probabilities of each having o? 01:12:31 Silvana Larrea: By multiplying those probabilites 01:12:32 Ijeoma Uche: .35 *.45 01:12:33 Julia Hankin: 0.45*0.35 01:12:37 Olufunke Fasawe: .35 + 0.45 01:14:33 Ala Koreitem: B 01:14:40 Ala Koreitem: And AB 01:14:41 Silvana Larrea: AB 01:15:53 Olufunke Fasawe: (0.45*0.35)+(0.4*0.27)+(0.11*0.26)+(0.04*0.12) 01:17:00 Hiruni Jayasekera (she/her): we’re thumbs upping! 01:17:02 Jessica Fields (she/her/hers): Im good! 01:17:04 Yulan Xie: ^^ 01:17:04 Michele Ko (she/her): #3! Haha 01:17:10 Jessica Fields (she/her/hers): Yeah let’s do #3! 01:17:12 Lupita Ambriz: Lets keep going:) 01:17:19 Olufunke Fasawe: I have put up two thumbs 01:19:19 Hiruni Jayasekera (she/her): the sample space is equal to 1 01:21:10 Ijeoma Uche: 1 01:21:19 Annalisa Watson (she/her): 1 - P(0 having O- blood) 01:21:24 Olufunke Fasawe: 1 - P(0, have O-blood) 01:22:15 Ijeoma Uche: 7.2 01:22:16 Olufunke Fasawe: 0.072? 01:22:16 Silvana Larrea: 0.072? 01:22:17 Aliza Adler: 7.2% 01:22:33 Chitra Nambiar: - 0.072 01:22:34 Olufunke Fasawe: So, not having O- blood will be 1-0.072 01:22:59 Chitra Nambiar: 1- 0.072 01:23:00 Annalisa Watson (she/her): =.928 01:23:01 Phoenix Ding: 1-0.072 01:25:08 Annalisa Watson (she/her): .928^10 01:25:13 Jessica Fields (she/her/hers): (P(one person having O- blood))^10 01:27:41 Annalisa Watson (she/her): No we need to subtract this from 1 01:27:42 Hiruni Jayasekera (she/her): is it 1-0.928^10? 01:27:43 Silvana Larrea: 1 - 0.4736? 01:28:19 Jessica Fields (she/her/hers): I know this is out of order, but could we review #12 after this? 01:28:25 Jessica Fields (she/her/hers): (And if not, no worries!) 01:28:58 Taylor Yoo: yes :) 01:29:26 Annalisa Watson (she/her): Could we start with 11!! 01:29:57 Ijeoma Uche: Yes can we start with 11 01:32:22 Nikki Marucut: yes 01:32:22 Hiruni Jayasekera (she/her): yes 01:34:40 Aliza Adler: Yeah I can’t see the formula, just the bottom part of the tree 01:36:11 Ijeoma Uche: .9985*.0060 01:36:15 Jessica Fields (she/her/hers): 0.015925 01:36:31 Ijeoma Uche: I got 0.005991 01:36:42 Chitra Nambiar: me too 01:36:52 Jessica Fields (she/her/hers): For 10, didn’t we have to do 0.01*0.9985 + 0.99*0.0060 01:37:43 Jessica Fields (she/her/hers): Great! Was just responding to a few folks in the chat who got something different 01:38:18 Ijeoma Uche: It came out to be correct when I checked 01:39:17 Aliza Adler: Can you just quickly explain that? 01:40:08 Yulan Xie: Where can we access the recorded videos again? 01:40:44 Ijeoma Uche: I tried this .9985/(.006+.9985) but its wrong lol 01:40:49 Arianna Libenson: isn’t 10 just 0.009985 + 0.00594 = 0.015925 01:40:54 Annalisa Watson (she/her): 0.01*0.9985/(0.01*0.9985 + 0.99*0.0060) 01:41:34 Christopher Patterson: P(HIV+ AND test+) / P(test +) 01:45:48 Ijeoma Uche: P(T = positive|A= antibody present) 01:45:55 Annalisa Watson (she/her): Person has the disease and tests positive for it 01:46:08 Ijeoma Uche: P(T = negative|A= antibody absent) 01:46:35 Annalisa Watson (she/her): Thanks! 01:46:57 Ijeoma Uche: P(A=antibody present|T=positive) 01:47:00 Annalisa Watson (she/her): Is it #11 01:49:16 Ijeoma Uche: 99.4% 01:49:17 Phoenix Ding: 0.9940 01:50:07 Ijeoma Uche: Do we have to account prevalence ? 01:51:23 Jessica Fields (she/her/hers): Do we have to account for prevalence for sensitivity and specificity? Or only for PPV? 01:52:58 Ijeoma Uche: #14 pleaseee 01:53:52 Ijeoma Uche: .6^10 01:56:29 Hiruni Jayasekera (she/her): none? 01:59:39 Ijeoma Uche: Out of the 10? 01:59:43 Silvana Larrea: I have to go. Thanks Kelsey! 02:00:41 Ala Koreitem: 0.6^10 02:01:45 Cheyenne Pritchard: complement? 02:02:29 Ijeoma Uche: .006046618 02:02:36 Hiruni Jayasekera (she/her): .6^10 02:04:46 Cheyenne Pritchard: (not sedentary >= 1) = 1-p (not sedentary = 0) #Use the complement rule. When we read "at least 1 -> 1-P (1- probability of not sedentary) # 1-.4^10