Opal Banking Union, a large Australian bank, wants to determine the degree of customer satisfaction with its services. It commissions web developers to add a feature to their online banking app: after one month of use, each new customer receives a prompt which asks them to report any issues they have encountered by typing in a textbox. They can also dismiss the prompt by clicking "I haven't encountered any issues”. After collecting data for 12 months, the bank receives over 35,000 responses. Of these responses, 12,000 reported an issue, and the remainder selected “I haven't encountered any issues”. In their internal annual report, Opal Banking Union reports that roughly 30-40% of their customers were dissatisfied with the bank’s services, and thus they must do much more to improve the customer experience.

Marking scheme: