Results 1 to 2 of 2

Math Help - Lung Capacity(mean,standard deviation)

  1. #1
    Junior Member
    Joined
    Apr 2009
    Posts
    44

    Lung Capacity(mean,standard deviation)

    A biology teacher recorded the lung capacity of each 16 year old in her school. The eacher determined that the values were normally distributed with a mean of 3500 ml and a standard deviation of 300 ml. If 23 percent of the 16 year olds lung capacities were less than samanthas,what was samanthas lung capacity?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Oct 2008
    Posts
    206
    Quote Originally Posted by dan123 View Post
    A biology teacher recorded the lung capacity of each 16 year old in her school. The eacher determined that the values were normally distributed with a mean of 3500 ml and a standard deviation of 300 ml. If 23 percent of the 16 year olds lung capacities were less than samanthas,what was samanthas lung capacity?
    Hi dan123,

    Let X be the lung capacity.
    We know that P(X< \text{samanthas})= 0.23
    Let S be samanthas capacity:
    P(Z< \frac{S-3500}{300})=0.23
    From the table, I get -0.74, do check again, I'm bad at looking up the table.

    \frac{S-3500}{300}=-0.74
    Solve S.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Mean and Standard Deviation....
    Posted in the Statistics Forum
    Replies: 2
    Last Post: February 13th 2010, 04:05 PM
  2. Replies: 5
    Last Post: May 18th 2009, 05:14 AM
  3. standard deviation and mean deviation
    Posted in the Statistics Forum
    Replies: 1
    Last Post: March 16th 2008, 06:09 AM
  4. Standard Deviation help.
    Posted in the Statistics Forum
    Replies: 3
    Last Post: January 4th 2008, 06:51 AM
  5. standard deviation
    Posted in the Statistics Forum
    Replies: 1
    Last Post: December 5th 2007, 06:18 AM

Search Tags


/mathhelpforum @mathhelpforum