Wednesday, April 1, 2009

Statistics Questions

Find the mean, median and mode of the following groups:

1. 45, 50, 47, 47, 51, 53, 56, 58, 48, 49, 45, 50, 47, 46

2. 6, 8, 4, 8, 6, 9, 1, 2, 8, 4, 6, 7, 3, 7, 4, 3, 7, 7, 5


3. A class' test results are as follows:
75, 84, 99, 54, 88, 60, 45, 81, 49, 80, 55, 43, 21, 84, 85
What is the mean, median and standard deviation?

What is the standard deviation in the following sets:
4. 12, 15, 12, 13, 18, 19, 14

5. 100, 102, 108, 118, 107, 129, 111, 104
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14 comments:

  1. DarkyApril 4, 2009 at 10:02 AM

    . 45, 50, 47, 47, 51, 53, 56, 58, 48, 49, 45, 50, 47, 46

    x = 1/n En 1=1
    = 45 + 50 + 47 + 47 + 51 +53+ 56 + 58 + 48+ 49+ 45 + 50 + 47+ 46
    = 692
    1/14*692
    so the mean = 49.23

    median = the two middle numbers /2
    = 56+58/2
    = 57

    mode is the most frequent
    = 47

    ReplyDelete
  2. DarkyApril 4, 2009 at 10:06 AM

    6, 8, 4, 8, 6, 9, 1, 2, 8, 4, 6, 7, 3, 7, 4, 3, 7, 7, 5

    x = 6+8+4+8+6+9+1+2+8+4+6+7+3+7+4+3+7+7+5=105

    1/19 * 105
    mean = 5.53

    median = 4

    mode = 7

    ReplyDelete
  3. shottaApril 4, 2009 at 4:22 PM

    solution 1
    to find the mean - add all the numbers and divide the total by the no. of terms
    45 + 50 + 47 + 47 + 51 + 53 + 56 + 58 + 48 + 49 + 45 + 50 + 47 + 46 = 692/14
    mean = 49.42

    mode is the number that occur the most
    therefore mode = 47

    median is the number that occurs in the middle
    first we have to rearrange the numbers in assending order so
    45, 45, 46, 47, 47, 47, 48, 49 50, 50, 51, 53, 56, 58,

    since there are two middle numbers we find their mean
    hence median = (48+49)/2
    median = 48.5

    ReplyDelete
  4. shottaApril 4, 2009 at 4:39 PM

    .
    to find the mean - add all the numbers and divide the total by the no. of terms
    6 + 8 + 4 + 8 + 6 + 9 + 1 + 2 + 8 + 4 + 6 + 7 + 3 + 7 + 4 + 3 + 7 + 7 + 5
    mean = 105 / 19
    = 5.52

    mode is the number that occur the most
    therefore mode = 7

    median is the number that occurs in the middle
    first we have to rearrange the numbers in assending order so

    1, 2, 3, 3, 4, 4, 4, 5, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9

    since the number of terms is a odd number the median is the number that appears in the middle
    hence the median is = 6

    ReplyDelete
  5. shottaApril 4, 2009 at 5:57 PM

    solution 3
    to find the mean - add all the numbers and divide the total by the no. of terms

    75 + 84 + 99 + 54 + 88 + 60 + 45 + 81 + 49 + 80 + 55 + 43 + 21 + 84 + 85

    mean = 1003/15
    =66.87

    median
    median is the number that occurs in the middle
    first we have to rearrange the numbers in assending order so

    21, 43, 45, 49, 54, 55, 60, 75, 80, 81, 84, 84 85, 88, 99
    since the number of terms is a odd number the median is the number that appears in the middle
    hence the median is = 75

    standard deviation
    2104.1+569.7+478.3+319.34+165.6+140.9+47.2+67.6+172.4+199.7+293.4+293.4+328.7+446.5+1056.3
    =6204.8/14
    =443.2
    standard deviation = square root of 443.2
    =21.05

    ReplyDelete
  6. creApril 9, 2009 at 3:51 PM

    6, 8, 4, 8, 6, 9, 1, 2, 8, 4, 6, 7, 3, 7, 4, 3, 7, 7, 5

    q = 6+8+4+8+6+9+1+2+8+4+6+7+3+7+4+3+7+7+5=105

    1/19 * 105
    mean = 5.53

    median = 4

    mode = 7

    ReplyDelete
  7. creApril 9, 2009 at 3:52 PM

    solution 3
    to find the mean - add all the numbers and divide the total by the no. of terms

    75 + 84 + 99 + 54 + 88 + 60 + 45 + 81 + 49 + 80 + 55 + 43 + 21 + 84 + 85

    mean = 1003/15
    =66.87

    median
    median is the number that occurs in the middle
    first we have to rearrange the numbers in assending order so

    21, 43, 45, 49, 54, 55, 60, 75, 80, 81, 84, 84 85, 88, 99
    since the number of terms is a odd number the median is the number that appears in the middle
    hence the median is = 75

    standard deviation
    2104.1+569.7+478.3+319.34+165.6+140.9+47.2+67.6+172.4+199.7+293.4+293.4+328.7+446.5+1056.3
    =6204.8/14
    =443.2
    standard deviation = square root of 443.2
    =21.05

    ReplyDelete
  8. sky captainApril 11, 2009 at 6:55 AM

    Q.#.1
    solution
    • The mean is the sum of all the numbers, divided by the sum of all terms
    = [45 + 50 + 47 + 47 + 51 + 53 + 56 + 58 + 48 + 49 + 45 + 50 + 47 + 46] = [692/14]
    mean = 49.42

    • The mode is the number that occur the most. = [45,50,47,47,51,53,56,58,48,49,45,50,47,46].
    The mode = 47

    • The median is the middle number.
    Arrange the numbers in ascending or descending order.
    45, 45, 46, 47, 47, 47, 48, 49 50, 50, 51, 53, 56, 58.

    Since there are two middle numbers we add them up and divide them by 2.
    = (48+49)/2
    = 48.5

    ReplyDelete
  9. sky captainApril 11, 2009 at 6:56 AM

    Q.#.2
    solution
    • The mean is the sum of all the numbers, divided by the sum of all terms
    =[6+ 8+ 4+ 8+ 6+ 9+ 1+ 2+ 8+ 4+ 6+ 7+ 3+ 7+ 4+ 3+ 7+ 7+ 5 = [105/19]
    mean = 5.526

    • The mode is the number that occur the most. = [6,8,4,6,9,1,2,8,4,6,7,3,7,4,3,7,7,5].
    The mode = 7.

    • The median is the middle number.
    Arrange the numbers in ascending or descending order.
    = [1,2,3,3,4,4,4,5,6,6,6,7,7,7,7,8,8,8].

    Since there are two middle numbers we add them up and divide them by 2.
    = (6+6)/2
    = 6.

    ReplyDelete
  10. computationApril 25, 2009 at 8:47 AM

    1.45, 50, 47, 47, 51, 53, 56,58,48,49,45,50, 47, 46
    mean= the sum of all the numbers divided by the amount of no.

    692/14=49.43

    median= the middle number when arranged in either acending or decending order if there is two middle numbers you would have to add them an then divided them by two ........

    the followin number were arranged in acending..

    45,45,46,47,47,47,48,49,50,50,51,53,56,58

    =48+49
    =97/2
    =48.5

    mode is the most frequent ocurring number
    =47

    ReplyDelete
  11. computationApril 25, 2009 at 8:50 AM

    2. 6, 8, 4, 8, 6, 9, 1, 2, 8, 4, 6, 7, 3, 7, 4, 3, 7, 7, 5

    mean=105/19
    =5.23

    median= 1,2,3,3,4,4,4,5,6,6,6,7,7,7,7,8,8,8,9
    = 6

    mode=7

    ReplyDelete
  12. computationApril 25, 2009 at 8:59 AM

    question 3.

    A class' test results are as follows:
    75, 84, 99, 54, 88, 60, 45, 81, 49, 80, 55, 43, 21, 84, 85
    What is the mean, median and standard deviation?

    mean=1003/15
    =66.87

    median=21,43,45,49,54,55,60,75,80,81,84,84,
    85,88,99

    median=75

    "STANDARD DEV."
    steps for calculating
    1.find the mean
    2.subtract the mean from each member
    3.square the difference
    4.find the sum of these squares
    5.divide this sum by n-1
    6.find the square root of this result

    =66.1+293.5+1032.34+165.7+446.5+47.2+478.3+199.7+319.3+172.4+140.9+569.8+2104.1+293.4+
    328.7

    =6657.24/14

    =475.5

    =root of 475.5

    =21.8

    ReplyDelete
  13. computationApril 25, 2009 at 9:03 AM

    question 4.
    What is the standard deviation in the following sets:
    12, 15, 12, 13, 18, 19, 14

    mean=103/7
    =14.7

    standard dev
    = 7.29+0.009+7.29+2.89+10.89+18.49+0.49
    =47.43/6
    =7.905
    root of 7.905
    =2.81

    ReplyDelete
  14. computationApril 25, 2009 at 9:07 AM

    question 5.
    What is the standard deviation in the following sets:
    100, 102, 108, 118, 107, 129, 111, 104

    mean=879/8
    =109.9

    standard dev...
    =98.01+62.41+3.61+65.61+8.41+364.81+1.21+
    34.81
    =638.88/7
    =91.3
    root of 91.3
    =9.55

    ReplyDelete

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