# random probability question

• Feb 3rd 2008, 11:35 AM
Cribster01
random probability question
How do I work out a formula to answer the following question

If a person is randomly selected, find the probability that his or her B/day is not in may? Ignore leap years.
what kind of probability should I be using? I.E Discreet probability distribution, binomial probabilty, or std normal distribution. any help appreciative!!!

I am totally lost for a proper equation for this(Whew)
• Feb 3rd 2008, 12:37 PM
CaptainBlack
Quote:

Originally Posted by Cribster01
How do I work out a formula to answer the following question

If a person is randomly selected, find the probability that his or her B/day is not in may? Ignore leap years.
what kind of probability should I be using? I.E Discreet probability distribution, binomial probabilty, or std normal distribution. any help appreciative!!!

I am totally lost for a proper equation for this(Whew)

Assume that a person chosen at random is equally likely to have any day
of the year as birthday.

Probability that birthday is in May = (number of days in May)/(number of days in year)

RonL
• Feb 4th 2008, 04:54 AM
colby2152
Quote:

Originally Posted by Cribster01
How do I work out a formula to answer the following question

If a person is randomly selected, find the probability that his or her B/day is not in may? Ignore leap years.
what kind of probability should I be using? I.E Discreet probability distribution, binomial probabilty, or std normal distribution. any help appreciative!!!

I am totally lost for a proper equation for this(Whew)

No distributions. There is only one data point. Use straight probability as CaptainBlack said.
• Feb 5th 2008, 04:15 PM
Cribster01
Than you all for your help....case closed. I do have another I will post on a new thread