Your cousin Mary has just taken over as manager of the up-and-coming fast food outlet Quickburger. She feels there is a

[answerhappygod]

Your cousin Mary has just taken over as manager of the
up-and-coming fast food outlet Quickburger. She feels there
is a lot of potential for improvement but wants to base any changes
she makes on evidence. Knowing your expertise with data
analysis and probability, she asks for your advice on a number of
topics.
Mary has asked customers to show on their way out how much they
liked their visit to Quickburger, by tapping one of five buttons
labelled 1, 2, 3, 4, 5, where a higher number tapped means a higher
level of satisfaction.