Results 1 to 3 of 3

Math Help - About Mean, Median, Mode, Standard deviation

  1. #1
    Newbie ilovepsycho's Avatar
    Joined
    Mar 2010
    From
    South Korea
    Posts
    9

    About Mean, Median, Mode, Standard deviation

    1. What is the mean, median, mode, and standard deviation for the following 13 items:
    1,4,2,3,1,2,5,2,3,2,7,4,2

    I solved this question:
    1. mean is 2.92
    2. median is 2
    3. mode is 2
    4. standard deviation is 0.49

    My answers are correct? Your checks are needed and will be a big help for me.

    2. There are two types of university entrance exams in US: SAT and ACT. Both of them are
    standardized test. Midwestern schools use ACT for admission, rather than the SAT. You got a debate
    with your friends which school has better undergraduates. One way to compare the quality of students is
    to compare standardized test scores. Unfortunately, School A, like many Midwestern schools, uses the
    ACT for admission, rather than the SAT, the test of choice for School B. The ACT has a top score of 36
    and SAT scores can be converted into ACT scores using the equation ACT = -3.4 + 0.02339(SAT).
    School B’s entering freshman class has a mean SAT score of 1230 and a standard deviation of 240.
    School A has a mean ACT of 26.9 and a standard deviation of 5.4. Convert school B’s mean and standard
    deviation of SAT scores to ACT scale.


    Summary:
    A uses ACT and A's mean is 26.9 and standard deviation 5.4
    B uses SAT and B's mean is 1230 and standard deviation 240

    My stuck point is that can B's mean or standard deviation just be inserted into the above equation, ACT= -3.4 + 0.02339(SAT) and converted into ACT scores? Thus, B's mean converted into an ACT score is 25.3697 and standard deviation 2.2136? Right? Your help is strongly needed. Please check my answers.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Quote Originally Posted by ilovepsycho View Post
    4. standard deviation is 0.49

    The only one I don't agree with. I get 1.7, how did you arrive at your answer?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie ilovepsycho's Avatar
    Joined
    Mar 2010
    From
    South Korea
    Posts
    9
    Quote Originally Posted by pickslides View Post
    The only one I don't agree with. I get 1.7, how did you arrive at your answer?
    Through the formula: sqrt {{(sigma x^2 - (sigma x)^2/n}/n-1}
    The others correspond to my answers?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Mean, Standard Deviation, Median
    Posted in the Statistics Forum
    Replies: 1
    Last Post: March 17th 2011, 03:35 PM
  2. Mean, Median, Range, IQR, Standard Deviation...
    Posted in the Statistics Forum
    Replies: 1
    Last Post: June 30th 2010, 10:04 PM
  3. Replies: 4
    Last Post: May 30th 2009, 03:12 AM
  4. Mean, Mode, Median, Standard Deviation
    Posted in the Statistics Forum
    Replies: 4
    Last Post: June 14th 2008, 02:49 PM
  5. Mean, Median, and standard deviation:
    Posted in the Statistics Forum
    Replies: 2
    Last Post: March 25th 2008, 08:42 AM

Search Tags


/mathhelpforum @mathhelpforum