PLEASE HELP A company is preparing to launch a new web site

PLEASE HELP!!

A company is preparing to launch a new web site to sell its products. From past experience, they know that purchases at the site will occur as a Poisson process with on average 22 purchases every 10 minutes.

What is the probability that the sixth purchase will occur between 2.27 minutes and 3.18 minutes after the site opens? Give your answer to four decimal places.