formula help!

[JamiePasley]

So I have been doing some simulations and using the rand() feature. The problem I am having now is I need to make a formula that generates a random number between 10500 and 30000 in increments of 250 (thats what is throwing me). Any help would be greatly appreciated!

 

[barry houdini]

Hello Jaime,

This formula will generate such a number

=INT(RAND()*79+42)*250

 

[JamiePasley]

Thank you so much! I am so glad I found this board. Another question I have is I am having a really hard time with probabilities right now I am running a sumulation of a business situation where I am generating random numbers for the two bids and I need the probability that one will be lower than the other. Any suggestions on this?
Thanks so much

 

[barry houdini]

I presume the random numbers are generated differently, otherwise the probability of one being greater than the other would be simply 50%

How are the random numbers generated?

 

[JamiePasley]

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the first being generated is using the formula =INT(lowest+(highest-lowest)*RAND()) which the highest is 30000 and the lowest is 10500 and the second is generated which the formula you provided (thanks again!) and I am trying to discover the probability of "winning" the bid or having the lowest

 

[c_m]

Both the formula generates random numbers uniformly distributed between 10500 and 30000. Therefore, on average, the probability of one number being higher than the other one is 50%.

 

[barry houdini]

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Note that if you use the formula

=INT(lowest+(highest-lowest)*RAND())

then it will never generate exactly the highest value. To do that you need to change to

=INT(lowest+(highest-lowest+1)*RAND())

 

[JamiePasley]

Thanks for the formula help I figured out what the problem is one bid is set to 13,000 the other varies with the formula <TABLE style="WIDTH: 265pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=353 border=0><COLGROUP><COL style="WIDTH: 265pt; mso-width-source: userset; mso-width-alt: 12909" width=353><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD class=xl63 style="BORDER-RIGHT: #f0f0f0; BORDER-TOP: #f0f0f0; BORDER-LEFT: #f0f0f0; WIDTH: 265pt; BORDER-BOTTOM: #f0f0f0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" width=353 height=17>=INT(lowest+(highest-lowest+1)*RAND())</TD></TR></TBODY></TABLE>
how would i figure out the probability of 13000 being higher than the random. lowest=10500 highest=30000

 

[c_m]

the probability of 13000 being higher than random
= (13000-10500)/(30000-10500)