Exam 1

  1. Metainformation

    Tag Value
    fileProbability_uva-variance-740-en_uva-variance-740-en
    nameuva-variance-740-en
    sectionProbability/Elementary Probability/Random variables/Variance
    typeschoice
    solutionFALSE, FALSE, TRUE, FALSE
    TypeConceptual
    LanguageEnglish
    LevelStatistical Literacy
    IRT-Difficulty2
    p-value0.5905

    Question

    MIT typically selects a few students each year who are eligible eligible for a prestigious award. Because very strict selection, each year the number of chosen students who qualify eligible for the award. The distribution of X, the number of selected students eligible each year, is as following:

    —————— —— —— —— —— —— —— —— —— Number of students 0 1 2 3 4 5 6 7 Chance 0.01 0.11 0.18 0.25 0.23 0.11 0.07 0.04 —————— —— —— —— —— —— —— —— ——

    What is the expected value and standard deviation of X?


    1. FALSE: ΜX = 2.24 and σX = 1.57
    2. FALSE: ΜX = 2.78 and σX = 1.69
    3. TRUE: ΜX = 3.39 and σX = 1.57
    4. FALSE: ΜX = 3.39 and σX = 1.86

    1. ΜX = 2.24 and σX = 1.57: Incorrect
    2. ΜX = 2.78 and σX = 1.69: Incorrect
    3. ΜX = 3.39 and σX = 1.57: Correct
    4. ΜX = 3.39 and σX = 1.86: Incorrect