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Business Statistics Homework Problems For 3rd

Problems on statistics and probability are presented. The answers to these problems are at the bottom of the page.

  1. Given the data set

    4 , 10 , 7 , 7 , 6 , 9 , 3 , 8 , 9

    Find

    a) the mode,

    b) the median,

    c) the mean,

    d) the sample standard deviation.

    e) If we replace the data value 6 in the data set above by 24, will the standard deviation increase, decrease or stay the same?



  2. Find x and y so that the ordered data set has a mean of 42 and a median of 35.

    17 , 22 , 26 , 29 , 34 , x , 42 , 67 , 70 , y



  3. Given the data set

    62 , 65 , 68 , 70 , 72 , 74 , 76 , 78 , 80 , 82 , 96 , 101,

    find

    a) the median,

    b) the first quartile,

    c) the third quartile,

    c) the interquartile range (IQR).



  4. The exam grades of 7 students are given below.

    70 , 66 , 72 , 96 , 46 , 90 , 50

    Find

    a) the mean

    b) the sample standard deviation



  5. Twenty four people had a blood test and the results are shown below.

    A , B , B , AB , AB , B , O , O , AB , O , B , A

    AB , A , O , O , AB , B , O , A , AB , O , B , A


    a) Construct a frequency distribution for the data.

    b) If a person is selected randomly from the group of twenty four people, what is the probability that his/her blood type is not O?



Answers to the Above Problems
Answers to the Above Questions
    1. The given data set has 2 modes: 7 and 9
    2. order data : 3 , 4 , 6 , 7 , 7 , 8 , 9 , 9 , 10 : median = 7
    3. (mean) : m = (3+4+6+7+7+8+9+9+10) / 9 = 7


    4. xx - m (x - m)2
      4-39
      1039
      700
      700
      6-11
      924
      3-416
      811
      924
      sum = 44


      sample standard deviation = 2.35 (rounded to 2 decimal places)

    5. The standard deviation will increase since 24 is further from away from the other data values than 6.


  1. x = 36 , y = 77

    1. median = 75

    2. first quartile = 69

    3. third quartile = 81

    4. interquartile range = 81 - 69 = 12


    1. mean = 70

    2. sample standard deviation = 18.6 (rounded to 1 decimal place)


    1. classfrequency
      A5
      B6
      AB6
      O

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