Results 1 to 3 of 3

Math Help - Last stat prob, I promise! heh

  1. #1
    Newbie
    Joined
    Aug 2007
    Posts
    6

    Last stat prob, I promise! heh

    Thanks
    Last edited by Smokey007; August 14th 2007 at 09:41 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Aug 2007
    Posts
    6
    need some help

    a. p(x>570)
    z509 = 570-509/112 = .54
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Smokey007 View Post
    Scores for men on the verbal portion of the SAT test are normally distributed with a mean of 509 and a standard deviation of 112.

    a. If 1 man is randomly selected, find the probability that his SAT verbal score is more than 570.
    p(z>(570-509)/112) = p(z>0.545) = 1 - p(z<0.545) ~= 1-0.707 = 0.293

    b. If 100 men are randomly selected, find the probability that their mean SAT verbal score is more than 570.
    The sample mean is normaly distributed with mean 509 and sd 112/sqrt(100)=11.2

    So we want:

    p(z>(570-509)/11.2) = p(z>5.45) ~= 0.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Stat/Prob help?
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 28th 2009, 05:14 AM
  2. PROB/STAT help
    Posted in the Statistics Forum
    Replies: 2
    Last Post: October 25th 2007, 04:11 PM
  3. Another stat prob
    Posted in the Statistics Forum
    Replies: 3
    Last Post: August 14th 2007, 08:46 PM
  4. Stat and prob help
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: April 22nd 2007, 06:56 AM
  5. college prob + stat
    Posted in the Statistics Forum
    Replies: 5
    Last Post: July 18th 2006, 07:53 PM

Search Tags


/mathhelpforum @mathhelpforum