The average number of customers that show up to a small boutique is 8 per hour (assume Poisson). A customer has just walked in. What is the probability that it will be at least 15 minutes before the next customer arrives?

I'm confused here because lambda seems to be 8 per hour, but we're being asked about this in a different way: probability that a certain amount of time will elapse. Does that mean that lambda is 7.5 minutes instead (1 customer walks into the shop every 7.5 minutes)?

Question

The average number of customers that show up to a small boutique is 8 per hour (assume Poisson).  A customer has just walked in.  What is the probability that it will be at least 15 minutes before the next customer arrives?  

I'm confused here because lambda seems to be 8 per hour, but we're being asked about this in a different way: probability that a certain amount of time will elapse.  Does that mean that lambda is 7.5 minutes instead (1 customer walks into the shop every 7.5 minutes)?

anonymous · Answer

ya i also think that your answer is right