some statistics help...

[KoopaTroopa]

alright this one's for you math/statistics people. i'm trying to estimate the number of guests at a wedding. so, basically i have an excel spreadsheet with all the guests. for each guest, i have a probability that he/she will attend the wedding. i also have a column that has the probability he/she will bring a guest, assuming that he/she will be attending the wedding. what's a good formula i can use to estimate the number of guests at the wedding??

for example, guest A, has a 25% chance of attending the wedding, but has a 100% chance of bringing a guest if he does come.

thanks!!

 

[LegendKiller]

Originally posted by: KoopaTroopa
alright this one's for you math/statistics people. i'm trying to estimate the number of guests at a wedding. so, basically i have an excel spreadsheet with all the guests. for each guest, i have a probability that he/she will attend the wedding. i also have a column that has the probability he/she will bring a guest, assuming that he/she will be attending the wedding. what's a good formula i can use to estimate the number of guests at the wedding??

for example, guest A, has a 25% chance of attending the wedding, but has a 100% chance of bringing a guest if he does come.

thanks!!

=Guest*ProbabilityGuest+GuestGuest*probabilityGuest*ProbabilityGuestGuest

Just fill that in for every cell, you'd have 5 columns (assuming only 1 possible guest of a guest). Guest, Probability of Guest, GuestGuest, and Probability of GuestGuest, and final outcome.


Thus, in your example, you'd have GuestA*.25+GuestB*1*.25 = .5 Expected Guest


If it was only a 50% chance of having a guest guest then it would = .375 guest.

 

[iamwiz82]

Not to be rude or anything, but you are a nerd

 

[KoopaTroopa]

Originally posted by: LegendKiller

Originally posted by: KoopaTroopa
alright this one's for you math/statistics people. i'm trying to estimate the number of guests at a wedding. so, basically i have an excel spreadsheet with all the guests. for each guest, i have a probability that he/she will attend the wedding. i also have a column that has the probability he/she will bring a guest, assuming that he/she will be attending the wedding. what's a good formula i can use to estimate the number of guests at the wedding??

for example, guest A, has a 25% chance of attending the wedding, but has a 100% chance of bringing a guest if he does come.

thanks!!

=Guest*ProbabilityGuest+GuestGuest*probabilityGuest*ProbabilityGuestGuest

Just fill that in for every cell, you'd have 5 columns (assuming only 1 possible guest of a guest). Guest, Probability of Guest, GuestGuest, and Probability of GuestGuest, and final outcome.


Thus, in your example, you'd have GuestA*.25+GuestB*1*.25 = .5 Expected Guest


If it was only a 50% chance of having a guest guest then it would = .375 guest.

awesome!!!

i think this will work...let me try it out

 

[BooGiMaN]

are you trying to figure out how much food and drinks to buy?

umm if you send out x invitations you need to have food and drink available for x amount of people...

otherwise its like writing a check with insufficient funds.....

yeah i know a lot of them wont show up..but what if more than you calculated show up..what are you going to do have them do.... share plates?

 

[LegendKiller]

Originally posted by: BooGiMaN
are you trying to figure out how much food and drinks to buy?

umm if you send out x invitations you need to have food and drink available for x amount of people...

otherwise its like writing a check with insufficient funds.....

yeah i know a lot of them wont show up..but what if more than you calculated show up..what are you going to do have them do.... share plates?

iamwiz82: Whois the geek, me or him?


Definitely not true. My wife and I got married last Dec. we utilized a %, like above and some advanced working of the list to estimate who was and who wasn't going to come. We sent out something like 170 possible invitations and had only 85 show up (95% of invites were out of state).

I had planned for 82 and built in a 10 person "cushion" assuming that those who didn't show would be outnumbered by those who said they wouldn't and did.

I was right on the money, more or less.

 

[iamwiz82]

Originally posted by: LegendKiller

Originally posted by: BooGiMaN
are you trying to figure out how much food and drinks to buy?

umm if you send out x invitations you need to have food and drink available for x amount of people...

otherwise its like writing a check with insufficient funds.....

yeah i know a lot of them wont show up..but what if more than you calculated show up..what are you going to do have them do.... share plates?

iamwiz82: Whois the geek, me or him?


Definitely not true. My wife and I got married last Dec. we utilized a %, like above and some advanced working of the list to estimate who was and who wasn't going to come. We sent out something like 170 possible invitations and had only 85 show up (95% of invites were out of state).

I had planned for 82 and built in a 10 person "cushion" assuming that those who didn't show would be outnumbered by those who said they wouldn't and did.

I was right on the money, more or less.

The OP, however when we got married, the final total wasn't due until two week before, so we already knew exactly how many were coming. Very few people will send in a response and then do the opposite. I believe we had one not show.