Timeline for Normal V Binomial Distribution (Elementary Question)
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Sep 10, 2019 at 14:00 | answer | added | Emil | timeline score: 1 | |
| Sep 10, 2019 at 3:15 | comment | added | Ruby Pa | @whuber So what would an approximate binomial distribution look like for this question? Is the process to arrive at this a lot more complicated than it would be for a normal, and that's a possible indication as to why normal is used? | |
| Sep 10, 2019 at 3:13 | comment | added | Ruby Pa | @Emil Due to the assumption, I found probability of a girl is 0.5. So the probability of three girls is P(GGG) = (1/2)^3 = 0.125. So, P(X=3) where X is the a girl is 0.125. For P(X=1) we have P(GB, BG, BBG) = (0.5)^2 + (0.5)^2 + (0.5)^3 = 0.625. I did this for P(X = 0, 1, 2, 3) and that gave me E(X) = 0(0.125)+1(0.625)+2(0.125)+3(0.125) = 1.25. | |
| Sep 9, 2019 at 14:09 | comment | added | Emil | Might I ask how you calculated $\mathbb{E}[X]$ to be $1.25$ ? | |
| Sep 9, 2019 at 13:53 | history | edited | Ruby Pa |
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| Sep 9, 2019 at 13:39 | comment | added | whuber♦ | This exercise asks for an approximation. Yes, you could approximate the distribution with a Binomial--but that would still be an approximation. (The exact answer is a little complicated, which is the implicit motivation for seeking an approximation.) | |
| Sep 9, 2019 at 13:11 | comment | added | Michael R. Chernick | This question requires the self study tag. | |
| Sep 9, 2019 at 12:05 | review | First posts | |||
| Sep 9, 2019 at 13:12 | |||||
| Sep 9, 2019 at 12:05 | history | asked | Ruby Pa | CC BY-SA 4.0 |