p**e
发帖数: 41 | 1 1, Assume you have 4 sets of porkers, which are the same, each containg 52
cards. Put them (i.e. 208 cards) into a line. What is the number of
possible permutations?
2, Random walk,starting from point 0, with probabilty 0.5 for +2 steps and
with probablity 0.5 for -1 steps, Q: what is the prob of hitting the point
-1.
3, In linear regression estimation, how to handle with those wild outliers ? | j*****4
发帖数: 292 | 2 1. 208!/(4!)^52
point
outliers ?
【在 p**e 的大作中提到】
: 1, Assume you have 4 sets of porkers, which are the same, each containg 52
: cards. Put them (i.e. 208 cards) into a line. What is the number of
: possible permutations?
: 2, Random walk,starting from point 0, with probabilty 0.5 for +2 steps and
: with probablity 0.5 for -1 steps, Q: what is the prob of hitting the point
: -1.
: 3, In linear regression estimation, how to handle with those wild outliers ?
| s*******s
发帖数: 1568 | 3 1. P(208)/P(4)^52?
3. trimmed linear regression
2. don't know, hehe
point
outliers ?
【在 p**e 的大作中提到】
: 1, Assume you have 4 sets of porkers, which are the same, each containg 52
: cards. Put them (i.e. 208 cards) into a line. What is the number of
: possible permutations?
: 2, Random walk,starting from point 0, with probabilty 0.5 for +2 steps and
: with probablity 0.5 for -1 steps, Q: what is the prob of hitting the point
: -1.
: 3, In linear regression estimation, how to handle with those wild outliers ?
| z****e
发帖数: 2024 | 4 for 3, you may need to review the following key concepts:
studentized deleted residuals, cook's distance, Mahalonobis distance, robust
model test. | S*********g
发帖数: 5298 | 5 2: (sqrt(5)-1)/2
point
outliers ?
【在 p**e 的大作中提到】
: 1, Assume you have 4 sets of porkers, which are the same, each containg 52
: cards. Put them (i.e. 208 cards) into a line. What is the number of
: possible permutations?
: 2, Random walk,starting from point 0, with probabilty 0.5 for +2 steps and
: with probablity 0.5 for -1 steps, Q: what is the prob of hitting the point
: -1.
: 3, In linear regression estimation, how to handle with those wild outliers ?
| J******d
发帖数: 506 | 6 到底是两道还是三道啊？
难道这个面试其实是考数数？
point
outliers ?
【在 p**e 的大作中提到】
: 1, Assume you have 4 sets of porkers, which are the same, each containg 52
: cards. Put them (i.e. 208 cards) into a line. What is the number of
: possible permutations?
: 2, Random walk,starting from point 0, with probabilty 0.5 for +2 steps and
: with probablity 0.5 for -1 steps, Q: what is the prob of hitting the point
: -1.
: 3, In linear regression estimation, how to handle with those wild outliers ?
| o****b
发帖数: 31 | 7 好像是三道。
1. P(208)/P(4)^52
2. (sqrt(5)-1)/2
3. 不知，swordmans 可不可以解释一下trimmed linear regression | Q***5
发帖数: 994 | 8 Remind me of a joke:
a math student went to an interview for a teaching position at a university.
All went well until he made the statement: there are three types of
mathematicians, those who can count and those who can not.
【在 J******d 的大作中提到】
: 到底是两道还是三道啊？
: 难道这个面试其实是考数数？
:
: point
: outliers ?
| b******9
发帖数: 47 | 9 any details about solving the part 2 to get (sqrt(5)-1)/2? Thanks | S*********g
发帖数: 5298 | 10 P(0->-1) = 1/2 + 1/2 P(2->-1)
P(2->-1)= P(0->-1)^3
【在 b******9 的大作中提到】
: any details about solving the part 2 to get (sqrt(5)-1)/2? Thanks
| b******9
发帖数: 47 | | k***y
发帖数: 25 | 12 why P(2->-1)= P(0->-1)^3? It can go to 4 from 2, right?
【在 S*********g 的大作中提到】
: P(0->-1) = 1/2 + 1/2 P(2->-1)
: P(2->-1)= P(0->-1)^3
| j***w
发帖数: 5379 | | h**6
发帖数: 4160 | 14 P(0->-1) = 1/2 + 1/2 P(2->-1)
P(2->-1)= P(0->-1)^3
根据这个式子，如果题目改为50%概率向正负各走一步，那么到达-1点的概率是1，对吗？ |
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