Results 1 to 2 of 2

Math Help - normal distribution

  1. #1
    Member
    Joined
    Jul 2006
    Posts
    95

    normal distribution

    Hello,
    plz try to solve this question.
    Thanks.
    Question:
    Given a normal distribution with μ=40 and σ = 6 , find
    (a) the area below 32
    (b) the area above 27
    (c) the area between 42 and 51
    (d) the x value that has 45% of the area below it
    (e) the x value that has 13% of the area above it
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    10
    Quote Originally Posted by m777 View Post
    Given a normal distribution with μ=40 and σ = 6 , find
    (a) the area below 32
    Find the z-score,
    \frac{40-32}{6} = z \to z =1.33
    The corresponding value is .408 on the table.
    Thus, P(32 \leq x \leq 40) = .408.
    But then,
    P(x\leq 32) + P(32\leq x \leq 40) = .5
    Thus,
    P(x\leq 32) = .092
    (b) the area above 27
    Find the corresponding z-score:
    \frac{40-27}{6}\approx 2.166
    The corresponding value is .484
    Thus,
    P(27\leq x\leq 40) = .484
    But then,
    P(27\leq x) = P(27\leq x \leq 40)+P(40\leq x) = .484+.5 = .984
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 27th 2011, 02:08 PM
  2. normal distribution prior and posterior distribution proof
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: March 9th 2011, 07:12 PM
  3. Replies: 2
    Last Post: March 29th 2010, 03:05 PM
  4. Replies: 3
    Last Post: February 6th 2009, 04:59 AM
  5. Replies: 1
    Last Post: April 20th 2008, 07:35 PM

Search Tags


/mathhelpforum @mathhelpforum