Basic binomial question The following appeared on an assignment of mine (already turned in). I contend that not enough information is given to provide an answer.... it seems pretty cut and clear to me. However, instructor insisted it's solvable in minitab. Can you help me figure out what I'm not understanding?  
How do you solve this without a model of distribution of weekly demand, or at least an average value to use as constant approximation. I must be missing something simple.  
The problem:  
Consider a service company.  
10% of the weekly demand is for a service category named "X" [Assume service categories are mutually exclusive].  
The company must revise their resource plan iff there are too few customer orders(less than one/week) or too many customer orders (more than five/week) of service category "X".  
For the next 12 weeks, what is the probability that the company will not need to revise the resource plan?  
Thanks
 A: This depends on the total number of customer orders; consider the situation if you have just one order per week. Then you are almost certainly have less than one in any given week. OTH if you have 1000 customers, you will have about 100 ordering "X" each week which is too much.
It's also not clear if the 10% is an average or a fixed number; the same is the case for the missing number of orders per week. The most likely way to interpret this question is to assume that each customer order has a chance of 10% of belonging to category "X" - but then we will still need the number of customer orders. If the number of orders is fixed then X the number of orders of "X" per week would be binomially distributed and the question would be solvable.
I think it is really questionable to claim that it is "solvable in Minitab" and give no theoretical background. There may be a button in Minisab that takes these numbers and gives an answer, but is it the answer to the question as it is stated here?  
Short version, I agree with you.
