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  • session#5 Divnyi Jnos @divenyi.janos

  • b.socrative.com

    Student login into room BMEADAT

  • How to find answersto relevant questions

    using data

  • QUESTION

    DATA

    ANALYSIS

    PRESENTATION

  • QUESTION

    DATA

  • QUESTION

    DATA

    ANALYSIS

  • P(A|B)

    conditional probability

    probability that A occurs given that B has occurred

  • E(Y|X)

    cond. expected value

    expected value of variable Ygiven that X takes a given value

  • E(Y) = a + bX

    linear regression

    if E(Y|X) is linear

    the regression function is it

  • The Case of Berkeley (1973)

    University of California, Berkeleywas sued for bias against women

    who had applied for admissionto graduate schools there.

  • Men Women

    Applicants Admitted Applicants Admitted

    ALL 2590 46% 1835 30%

    ALL 2590 46% 1835 30%

  • Men Women

    Applicants Admitted Applicants Admitted

    ALL 2590 46% 1835 30%

  • DepartmentMen Women

    Applicants Admitted Applicants Admitted

    A

    B

    C

    D

    E

    F

    ALL 2590 46% 1835 30%

  • DepartmentMen Women

    Applicants Admitted Applicants Admitted

    A 825 62% 108 82%

    B 560 63% 25 68%

    C 325 37% 593 34%

    D 417 33% 375 35%

    E 191 28% 393 24%

    F 272 6% 341 7%

    ALL 2590 46% 1835 30%

  • DepartmentMen Women

    Applicants Admitted Applicants Admitted

    A 825 62% 108 82%

    B 560 63% 25 68%

    C 325 37% 593 34%

    D 417 33% 375 35%

    E 191 28% 393 24%

    F 272 6% 341 7%

    ALL 2590 46% 1835 30%

  • xkcd.com/552

  • Mr. Allen, the candidate for politicalParty A will run against Mr. Baker of Party B for office. Past races betweenthese parties for this office werealways close, and it seems that thisone will be no exception Party A candidates always have gottenbetween 40% and 60% of the vote and have won about half of the elections.

    Carl Morris (1987)

  • QUESTION

    Mr. Allen needs to know whether he is going to win the election, so he ordersa poll. Which of three outcomes wouldbe the most encouraging for him?

    (a) Y = 15, n = 20

    (b) Y = 115, n = 200

    (c) Y = 1046, n = 2000

    Carl Morris (1987)