Tuesday, March 10, 2009

5:30 PM: Maleda Scott has entered the room.
5:33 PM: John Frantz has entered the room.
5:33 PM: John Frantz has left the room.
5:34 PM: Maleda Scott has left the room.
5:38 PM: John Frantz has entered the room.
5:48 PM: John Frantz has left the room.
5:48 PM: John Frantz has entered the room.
5:51 PM: Margaret Cannella has entered the room.
5:52 PM: John Frantz: Heylo
5:55 PM: Margaret Cannella: HEY WHATS UP
5:55 PM: John Frantz: Not a lot.
5:55 PM: John Frantz: Numb face from dental work. Wheee!
5:55 PM: Margaret Cannella: WHAT DID YOU HAVE DONE?
5:56 PM: John Beck(Ins) has entered the room.
5:56 PM: John Frantz: Two fillings and a cleaning.
5:56 PM: John Beck(Ins): Hi, Margaret and John!
5:56 PM: Margaret Cannella: HELLO
5:56 PM: Andrea Scurti has entered the room.
5:56 PM: John Frantz: Hello
5:56 PM: John Beck(Ins): Hi, Andrea!
5:57 PM: Andrea Scurti: hello!
5:57 PM: John Beck(Ins): So how are things back in Baltimore?
5:57 PM: John Frantz: Fine for the most part.
5:58 PM: Andrea Scurti: just waiting for summer!
5:58 PM: Marcus Buckley has entered the room.
5:58 PM: John Beck(Ins): Good!
5:58 PM: Danielle Ryan has entered the room.
5:58 PM: John Beck(Ins): Hi, Marcus and Danielle!
5:58 PM: Marcus Buckley: Hello
5:58 PM: Danielle Ryan: Good evening!
5:59 PM: Salina Wiggins has entered the room.
5:59 PM: John Beck(Ins): HI, Salina!
5:59 PM: Salina Wiggins: hi professor beck
6:02 PM: John Beck(Ins): Okay, Class, it's 6:00 so let's get started. Let me know when you are on L6, p1, please.
6:02 PM: Andrea Scurti: I'm good
6:02 PM: Marcus Buckley: ready
6:02 PM: John Frantz: I am.
6:02 PM: Danielle Ryan: I'm good to go.
6:02 PM: Stephanie Burke has entered the room.
6:02 PM: John Beck(Ins): Hi, Stephanie! We're on Ch 6, p1.
6:03 PM: Stephanie Burke: Hi! ok
6:03 PM: John Beck(Ins): According to our Venn diagram, Gary and Bob are not taking math or physics.
6:03 PM: John Beck(Ins): Andy, Edgar and Fred are taking both math and physics.
6:03 PM: John Beck(Ins): etc.
6:04 PM: John Beck(Ins): Go to page 2, please.
6:04 PM: John Beck(Ins): Go to page 3,please.
6:05 PM: John Beck(Ins): 3 of them are taking both subjects and there are a total of 10 students so the probability that your randomly selected student is taking both is 3/10
6:05 PM: John Beck(Ins): You could also represent that as .3
6:05 PM: John Beck(Ins): Go to page 4, please.
6:05 PM: John Beck(Ins): Boy, that looks complicated.
6:05 PM: Maleda Scott has entered the room.
6:06 PM: John Beck(Ins): Hi, Maleda!
6:06 PM: John Beck(Ins): Maleda, we're on Ch 6, p4.
6:06 PM: John Beck(Ins): Go to page 5, please.
6:06 PM: John Beck(Ins): 6 students are taking math, so P(math) = 6/10
6:07 PM: Rachel Kruger has entered the room.
6:07 PM: John Beck(Ins): 5 students are taking physics, so P(physics) = 5/10
6:07 PM: Rachel Kruger: Hi everyone...sorry I am late
6:07 PM: John Beck(Ins): Hi, Rachel! We're on Ch 6_p5.
6:07 PM: Rachel Kruger: thnx
6:07 PM: John Beck(Ins): Notice that we've counted Andy, Edgar and Fred twice.
6:07 PM: John Beck(Ins): we counted them when we counted the math students.
6:08 PM: John Beck(Ins): Then we counted them again when we counted the physics students.
6:08 PM: John Beck(Ins): Since we counted them twice, we'll subtract them out once.
6:08 PM: John Beck(Ins): Hence we subtract 3/10 which is the probability of taking both math and physics.
6:08 PM: John Beck(Ins): Okay?
6:08 PM: John Frantz: Gotcha
6:09 PM: Andrea Scurti: ok
6:09 PM: Danielle Ryan: ok
6:09 PM: Marcus Buckley: k
6:09 PM: Salina Wiggins: ok
6:09 PM: Stephanie Burke: I don’t get it
6:09 PM: John Beck(Ins): Go to page 6, please.
6:09 PM: John Beck(Ins): P(math) = 5/10
6:09 PM: John Beck(Ins): Nope, P(math) = 6/10
6:10 PM: Stephanie Burke: ok
6:10 PM: John Beck(Ins): Okay?
6:10 PM: Stephanie Burke: i got it now
6:10 PM: John Beck(Ins): Okay, go to page 6, please.
6:10 PM: John Beck(Ins): We have a common denominator so we add the numerators.
6:11 PM: John Beck(Ins): Go to page 7, please.
6:11 PM: John Beck(Ins): Always simplify your fractions.
6:11 PM: Sarah Brown has entered the room.
6:11 PM: John Beck(Ins): Hi, Sarah! We're on Ch 6_p7.
6:11 PM: Sarah Brown: Thanks!
6:11 PM: John Beck(Ins): Go to page 8, please.
6:12 PM: John Beck(Ins): Go to page 9, please.
6:12 PM: John Beck(Ins): Impossible event.
6:12 PM: John Beck(Ins): Go to page 10, please.
6:13 PM: John Beck(Ins): Disjoint sets have no elements in common.
6:13 PM: John Beck(Ins): Go to page 11, please.
6:13 PM: John Beck(Ins): Go to page 12,please.
6:13 PM: John Beck(Ins): Go to page 13,please.
6:14 PM: John Beck(Ins): Go to page 14, please.
6:14 PM: John Beck(Ins): P(math | physics) is read, "what is the probability that a person is taking math if we know he/she is taking physics."
6:15 PM: John Beck(Ins): Notice that the denominator of our probability fraction is P(physics)-- we are restricting our domain to those students who are taking physics.
6:16 PM: John Beck(Ins): The only people we are interested in are A, E, F, H, and J
6:16 PM: John Beck(Ins): They are the students who are taking physics.
6:16 PM: John Beck(Ins): Go to page 15, please.
6:16 PM: John Beck(Ins): Go to page 16, please.
6:17 PM: John Beck(Ins): Go to page 17, please.
6:17 PM: John Beck(Ins): I've inverted the denominator, 5/10, and I'm multiplying.
6:17 PM: John Beck(Ins): Okay?
6:17 PM: Rachel Kruger: ok
6:17 PM: Salina Wiggins: ok
6:17 PM: Sarah Brown: yup
6:17 PM: Danielle Ryan: ok
6:17 PM: Stephanie Burke: ok
6:17 PM: Marcus Buckley: ok
6:18 PM: Andrea Scurti: ok
6:18 PM: Maleda Scott: ok
6:18 PM: John Beck(Ins): Go to page 18, please.
6:18 PM: John Beck(Ins): Now let's look at a more straight forward way of working this problem.
6:18 PM: John Beck(Ins): Go to page 19, please.
6:19 PM: John Beck(Ins): n(math and physics) is read, "what is the cardinal number of the set (math and physics)"
6:19 PM: John Beck(Ins): Or more directly, "how many students are in the set, (math and physics)?
6:20 PM: John Beck(Ins): n(physics) is read, "how many students are in the set Physics?"
6:20 PM: John Beck(Ins): Go to page 20, please.
6:20 PM: John Beck(Ins): Go to page 21, please.
6:20 PM: John Beck(Ins): Much easier!
6:21 PM: Rachel Kruger: so much easier!
6:21 PM: John Beck(Ins): And it focuses on the fact that we've restricted our domain to the elements of the set, physics.
6:21 PM: John Beck(Ins): Okay, let's go to page 22, please.
6:22 PM: John Beck(Ins): Empirical evidence is based on experience rather than on science.
6:22 PM: John Beck(Ins): Go to page 23, please.
6:22 PM: John Beck(Ins): On his first presentation he either makes a sale or he doesn't. I've indicated the probabilities on the legs of the outcomes.
6:23 PM: John Beck(Ins): Go to page 24, please.
6:23 PM: John Beck(Ins): Here's our second presentation of the day.
6:23 PM: John Beck(Ins): Once again, regardless of the first outcome, we could either make a sale or fail to make a sale on our second presentation.
6:23 PM: John Beck(Ins): And the probabilities are indicated.
6:24 PM: John Beck(Ins): Go to page 25,please.
6:24 PM: John Beck(Ins): The SS leg has probability (1/5)(1/5) = 1/25
6:24 PM: John Beck(Ins): Go to page 26, please.
6:24 PM: John Beck(Ins): The SF leg has probability (1/5)(4/5) = 4/25
6:24 PM: John Beck(Ins): etc.
6:25 PM: John Beck(Ins): Go to page 27, please.
6:25 PM: John Beck(Ins): Go to page 28, ploease.
6:25 PM: John Beck(Ins): Now we need to look for the legs that represent exactly one sale.
6:25 PM: John Beck(Ins): Go to page 29, please.
6:26 PM: John Beck(Ins): Go to page 30, please.
6:26 PM: John Beck(Ins): By the way, what would you get if you added 1/25, 4/25, 4/25, and 16/25?
6:26 PM: Rachel Kruger: 1 whole
6:27 PM: John Beck(Ins): RIGHT
6:27 PM: John Beck(Ins): The sum of the probabilities of all of the possible outcomes will always add up to 1.
6:27 PM: John Beck(Ins): Go to page 31, please.
6:27 PM: Rachel Kruger: why is it 4/25 +4/25 for 1 sale?
6:28 PM: John Beck(Ins): Go to page 32, please.
6:28 PM: Rachel Kruger: why not 1/5 + 1/5
6:28 PM: John Beck(Ins): There are 6 cylinders
6:28 PM: John Beck(Ins): Oops, you're back on the sales problem.
6:29 PM: Rachel Kruger: yes
6:29 PM: Rachel Kruger: cannot tyoe fast enough!
6:29 PM: John Beck(Ins): P(sale) = 1/5 and P(fail) = 4/5
6:29 PM: John Beck(Ins): Okay?
6:29 PM: Rachel Kruger: but you want probability of 1 sale
6:30 PM: John Beck(Ins): I have to make two sales presentations.
6:30 PM: Rachel Kruger: oh oh ...got it! lol
6:30 PM: John Beck(Ins): On each of my presentations, P(sale) = 1/5
6:30 PM: John Beck(Ins): And on each presentation, P(fail) = 4/5
6:30 PM: Rachel Kruger: ok....the light bulb came on
6:30 PM: John Beck(Ins): OK, let's go back to page 31, please
6:31 PM: John Beck(Ins): Go to page 32, please.
6:31 PM: John Beck(Ins): On the first pull of the trigger, I either fire the blank, or the firing pin hits an empty cylinder.
6:32 PM: John Beck(Ins): Since there is only 1 blank cartridge and there are 6 cylinders, P(hit blank) = 1/6
6:32 PM: John Beck(Ins): Similary, P(hit empty cylinder) = 5/6
6:32 PM: John Beck(Ins): OKay?
6:32 PM: Sarah Brown: yup
6:32 PM: Rachel Kruger: ok
6:32 PM: Danielle Ryan: ok
6:32 PM: Marcus Buckley: ok
6:32 PM: Stephanie Burke: ok
6:32 PM: John Beck(Ins): Go to page 33, please.
6:32 PM: Maleda Scott: ok
6:32 PM: Salina Wiggins: ok
6:33 PM: John Beck(Ins): If I hit the blank cartridge on the first pull of the trigger, that branch is done.
6:33 PM: John Beck(Ins): If I don't hit it on the first pull, then on my second pull of the trigger I might hit the blank cartridge or I might have an empty cylinder.
6:34 PM: John Beck(Ins): P(B) = 1/5 since there is 1 blank cartridge and only 5 unused cylinders
6:34 PM: John Beck(Ins): P(empty) = 4/5 since 4 of the 5 unused cylinders do not have the blank cartridge.
6:34 PM: John Beck(Ins): With me?
6:34 PM: Danielle Ryan: yes
6:34 PM: Andrea Scurti: yes
6:34 PM: Salina Wiggins: yeah
6:34 PM: Marcus Buckley: yes
6:34 PM: Rachel Kruger: ok
6:34 PM: Sarah Brown: yes
6:35 PM: Maleda Scott: yes
6:35 PM: Stephanie Burke: yes
6:35 PM: John Beck(Ins): Go to page 34,please.
6:35 PM: John Beck(Ins): Go to page 35, please.
6:35 PM: John Beck(Ins): Go to page 36, please.
6:35 PM: John Beck(Ins): Go to page 37, please.
6:36 PM: John Beck(Ins): Those are the two "winning" outcomes-- hit the blank on the first pull or hit the blank on the second pull.
6:36 PM: John Beck(Ins): Go to page 38, please.
6:36 PM: John Beck(Ins): Go to page 39, please.
6:37 PM: John Beck(Ins): Always SIMPLIFY your fractions.
6:37 PM: Sarah Brown: always in fraction form?
6:37 PM: Sarah Brown: or can it be decimal?
6:37 PM: John Beck(Ins): Yes.
6:38 PM: John Beck(Ins): Let me qualify that. 1/3 is NOT equal to .3 or .33 or .333
6:38 PM: Sarah Brown: got it
6:39 PM: John Beck(Ins): Okay, class, that's it unless you have questions.
6:39 PM: Rachel Kruger: only about homework
6:39 PM: Sarah Brown: I have a question about number 4 in the homework.
6:39 PM: Rachel Kruger: 3/4
6:39 PM: John Beck(Ins): Okay, let me look at it.
6:39 PM: Sarah Brown: I always get messed up with poker questions
6:39 PM: Salina Wiggins: ok goodnight
6:40 PM: Maleda Scott: ? 4 homework
6:40 PM: Rachel Kruger: Mr Beck can you post what a straight and a flush etc are in cards...I have the biggest problem sorting that out!
6:40 PM: Stephanie Burke: how did we get 10\30 if we are adding 1\6+ 5\30
6:40 PM: John Beck(Ins): Rachel, they are defined in the Lessons in Chapter 3 under Poker Hands.
6:41 PM: Rachel Kruger: ok thanks
6:41 PM: John Beck(Ins): 1/6 = 5/30
6:41 PM: Andrea Scurti: I have a question about the last question on the exam
6:41 PM: Andrea Scurti: I looked everywhere and could not find that type of problem to relate to
6:41 PM: Stephanie Burke: ok thanks goodnight
6:41 PM: Stephanie Burke has left the room.
6:41 PM: John Beck(Ins): Stephanie, 1/6 + 5/30 = 5/30 + 5/30 Okay?
6:42 PM: Salina Wiggins: ok goodnight
6:42 PM: Andrea Scurti: I spent hours trying to figure it out @ home before the exam
6:42 PM: John Beck(Ins): What is the question, Andrea?
6:42 PM: Salina Wiggins has left the room.
6:42 PM: Andrea Scurti: At least one Ace
6:42 PM: Andrea Scurti: in a 5 card poker hand
6:42 PM: John Beck(Ins): That was in the section on "counting indirectly.
6:43 PM: Maleda Scott has left the room.
6:43 PM: Margaret Cannella has left the room.
6:44 PM: Rachel Kruger: on question 3 on the homework does 6.3.3.3 sound good
6:44 PM: Danielle Ryan: good night
6:44 PM: Danielle Ryan has left the room.
6:45 PM: Marcus Buckley has left the room.
6:45 PM: John Beck(Ins): Rachel, I don't understand 6.3.3.3
6:46 PM: Rachel Kruger: ok....n1 = p(6,6) n2 =3 n3=3 n4=3
6:46 PM: John Beck(Ins): YEs, that sounds pretty good.
6:46 PM: Rachel Kruger: yeah! thats
6:47 PM: Rachel Kruger: one more thing when I worked out c(52,5) I got a different answer to the lesson
6:48 PM: John Beck(Ins): I'm pretty certain I have it correct in the Lessons, Rachel.
6:49 PM: Rachel Kruger: oh I know that! when I worked it our by hand I got a different answer than the calcultor......can you not
6:49 PM: Rachel Kruger: cancel out the 5 into the 50
6:49 PM: Rachel Kruger: so you have 52 x 51 x 10 49 x 48
6:49 PM: John Beck(Ins): 2,598,960 is the correct answer.
6:50 PM: Sarah Brown: So number 4...mind helping me get started with it? I just get confused with all the
6:50 PM: John Beck(Ins): And in the denominator you have 5x4x3x2
6:50 PM: Sarah Brown: poker questions
6:51 PM: John Beck(Ins): OKay, let's look at P(1 pair)
6:52 PM: John Beck(Ins): put the cards into 13 piles - all aces in one pile, kings in one pile, etc.
6:52 PM: Sarah Brown: ok
6:52 PM: Andrea Scurti: goodnite everyone!
6:52 PM: Andrea Scurti has left the room.
6:52 PM: John Beck(Ins): G’night, Andrea.
6:53 PM: Sarah Brown: so it would be (13,1) right?
6:53 PM: John Beck(Ins): Right
6:53 PM: Sarah Brown: and then (4,2)?
6:53 PM: John Beck(Ins): RIGHT
6:53 PM: Sarah Brown: then i have a hard time with the last part
6:53 PM: Sarah Brown: I am not sure how many cards I have left to choose 3 from
6:53 PM: John Beck(Ins): Now you need three more piles. You will pick one card from each of those 3 piles.
6:54 PM: Sarah Brown: got it
6:54 PM: Sarah Brown: so i would have (12,3)?
6:54 PM: John Beck(Ins): GREAT
6:54 PM: John Beck(Ins): C(12,3)
6:54 PM: Sarah Brown: and then (4,1) for the rest
6:54 PM: John Beck(Ins): C(4,1)
6:54 PM: John Beck(Ins): YES
6:55 PM: Sarah Brown: the for a straight?
6:55 PM: John Beck(Ins): Start with 4 piles -- all clubs in one pile, all diamonds in one pile, etc.
6:55 PM: Sarah Brown: ok
6:55 PM: John Beck(Ins): pick a pile.
6:56 PM: Sarah Brown: ok
6:56 PM: John Beck(Ins): Then pick 5 cards from the pile you selected!
6:56 PM: Sarah Brown: ok
6:56 PM: John Beck(Ins): Life is good!
6:56 PM: Sarah Brown: is that it for b?
6:56 PM: John Beck(Ins): Yes
6:56 PM: Sarah Brown: is it possible to turn the homework in early tomorrow morning?
6:56 PM: John Beck(Ins): Don't forget that you need a denominator.
6:56 PM: John Beck(Ins): Yes
6:57 PM: Sarah Brown: thank you for your help!!
6:57 PM: John Beck(Ins): Have a good one!
6:57 PM: John Beck(Ins): G'night, Class.
6:57 PM: Sarah Brown has left the room.
6:57 PM: John Beck(Ins) has left the room.
6:57 PM: John Frantz: Night.
6:57 PM: Rachel Kruger has left the room.
7:06 PM: John Frantz has left the room.
7:29 PM: Toyia Haines has entered the room.
7:29 PM: Toyia Haines has left the room.