Maths Help!

[zilch4ry]

Hi all,

Right.. I have been given an A-level ICT task to complete which involves producing an answer that will later be placed into an excel spreadsheet. Basically the question I have is as follows: "if a supermarket has 20 tills, how would I work out the minimum number of tills needed open per hour, if a maximum of 4 customers are allowed to be queuing at 1 till at a time". I know the following figures:

• The average staff member can scan 1552 items per hour.
• The average customer purchases 60 items per hour.
• There are 147 customers per hour.

so is anybody can use those figures to determine the number of tills which need to be open with no more than 4 customer per till at any 1 time. Any help will be great, especially if you can post the steps you took to get to the final result.

Thanks in advance,




Tom

 

[shg]

147 customers buying 60 items/hr is 8820 items/hr, requiring 8820/1552 ~ 5.7 cashiers. Round that up to 6, and you can process 9312 items/hr, which is 155.2 customers.

Then (I think) you need to use POISSON to compute the probability that the number of customers in a given period is greater than 179 (i.e., is 155 (capacity with 6 cashiers) plus 6 (cashiers) times 4 (queue length)).

Maybe.

 

[zilch4ry]

Thank you for the help