Results 1 to 5 of 5

Math Help - Standard Norm. Distribution Curves

  1. #1
    Newbie
    Joined
    Apr 2008
    Posts
    4

    Standard Norm. Distribution Curves

    Ive been studying for a test ive got tomorrow, and i keep getting stuck on questions that i should know by now.-_-. heres some of them.

    Find the z value to the right of the mean so that:
    a. 53.98% of the area under the distribution curve lies to the left of it.
    b. 71.90% ' '
    c. 96.78% ' '

    Im using my TI-84 but i also have a normal distribution chart thing. I wasnt sure how to approach this kind of problem. I have a memory of doing them in class, but once im out of class its over.--_--

    thanks for the help
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by hemoglowen View Post
    Ive been studying for a test ive got tomorrow, and i keep getting stuck on questions that i should know by now.-_-. heres some of them.

    Find the z value to the right of the mean so that:
    a. 53.98% of the area under the distribution curve lies to the left of it.
    b. 71.90% ' '
    c. 96.78% ' '

    Im using my TI-84 but i also have a normal distribution chart thing. I wasnt sure how to approach this kind of problem. I have a memory of doing them in class, but once im out of class its over.--_--

    thanks for the help
    In each case you can use the invnorm command.

    You must have been shown how to do this ..... Go back to your class notes or textbook and review it.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2008
    Posts
    4
    ahh thats right. invnorm. thanks a bunch! In my scurry of mass studying, ive seemed to misplaced about three pages of my notes. if you dont mind me asking, what do i enter in the inverse normal command? is it the number given, which is 53.98% and the number left over from 100%? which would be 46.02%

    so, invrnorm(.5398,.4602)
    this gives me the answer of .5601

    by the way, thanks for the help so far.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by hemoglowen View Post
    ahh thats right. invnorm. thanks a bunch! In my scurry of mass studying, ive seemed to misplaced about three pages of my notes. if you dont mind me asking, what do i enter in the inverse normal command? is it the number given, which is 53.98% and the number left over from 100%? which would be 46.02%

    so, invrnorm(.5398,.4602)
    this gives me the answer of .5601

    by the way, thanks for the help so far.
    To get the value of z when you know Pr(Z < z)= a:

    The format of the command is as follows:

    invNorm(a, mean, standard deviation).

    In the absence of mean and standard deviation the calculator defaults to the standard normal.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Apr 2008
    Posts
    4
    Quote Originally Posted by mr fantastic View Post
    To get the value of z when you know Pr(Z < z)= a:

    The format of the command is as follows:

    invNorm(a, mean, standard deviation).

    In the absence of mean and standard deviation the calculator defaults to the standard normal.

    awesome, thanks. that was pretty much all i needed. maybe i should have asked for the format of the command like you said. Thanks again!
    hemoglowen
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: March 29th 2010, 03:05 PM
  2. Replies: 2
    Last Post: November 7th 2009, 01:13 PM
  3. standard distribution. Help!
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 21st 2009, 10:08 PM
  4. Standard Uniform Distribution
    Posted in the Statistics Forum
    Replies: 3
    Last Post: July 3rd 2009, 03:53 AM
  5. Using skewed distribution vs Standard Normal Distribution
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: September 26th 2007, 06:22 PM

Search Tags


/mathhelpforum @mathhelpforum