Results 1 to 2 of 2

Math Help - Homework 2

  1. #1
    Newbie
    Joined
    Mar 2008
    Posts
    5

    Homework 2

    A study of Hub Furniture regarding the payment of invoices reveals the time from billing until payment is received follows the normal distribution. The mean time until payment is received is 20 days and the standard deviation is 5 days.

    a. What percent of the invoices are paid within 15 days of receipt?

    b. What percent of the invoices are paid in more than 28 days?

    c. What percent of the invoices are paid in more than 15 days but less than 28 days?

    d. The management of Hub Furniture wants to encourage their customers to pay their monthly invoices as soon as possible. Therefore, it announced that a 2 percent reduction in price would be in effect for customers who pay within 7 days of the receipt of the invoice. What percent of customers will earn this discount?

    Hint: After deriving your answer, think about it logically. For example, can the probability that an invoice is paid in more than 28 days be greater than 0.5 when the mean is 20? No, it certainly must be less than 0.5, and probably much less.



    If the average number of defects in a Poisson distribution is 3, what is the probability of 2 or more defects?
    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 Aala View Post
    A study of Hub Furniture regarding the payment of invoices reveals the time from billing until payment is received follows the normal distribution. The mean time until payment is received is 20 days and the standard deviation is 5 days.

    a. What percent of the invoices are paid within 15 days of receipt?

    b. What percent of the invoices are paid in more than 28 days?

    c. What percent of the invoices are paid in more than 15 days but less than 28 days?

    d. The management of Hub Furniture wants to encourage their customers to pay their monthly invoices as soon as possible. Therefore, it announced that a 2 percent reduction in price would be in effect for customers who pay within 7 days of the receipt of the invoice. What percent of customers will earn this discount?

    [snip]
    Let X be the random variable number of days until payment.

    Then X ~ Norm (\mu = 20\, , \sigma = 5).

    a. 100 Pr(X < 15)

    b. 100 Pr(X > 28)

    c. 100 Pr(15 X < 28)

    d. 100 Pr(X < 7)

    In each case the calculation of the probability should be routine.


    Quote Originally Posted by Aala View Post
    [snip]
    If the average number of defects in a Poisson distribution is 3, what is the probability of 2 or more defects?
    1. As you should already realise, \Pr(X = x) = \frac{e^{-3} \, 3^x}{x!}.

    2. \Pr(X \geq 2) = 1 - \Pr(X \leq 1) = 1 - \Pr(X = 0) - \Pr(X = 1).
    Last edited by mr fantastic; March 7th 2008 at 07:07 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. homework help
    Posted in the Discrete Math Forum
    Replies: 4
    Last Post: August 31st 2009, 05:36 AM
  2. need help with homework
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: July 20th 2009, 09:34 AM
  3. homework help
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 10th 2009, 08:12 PM
  4. Homework Help
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 2nd 2007, 02:09 PM
  5. Homework Help
    Posted in the Math Topics Forum
    Replies: 9
    Last Post: October 14th 2007, 04:00 PM

Search Tags


/mathhelpforum @mathhelpforum