The interview can be broken in two categories... Case Interview and Behavioral Interview.
Case interview primarily checks your ability to interpret the data for example if you will be able to see if the company making profit for loss, percentage , graphical representation of data. Simple maths but I would suggest you should revise the formula's for Profit/ Loss and Break Even Analysis,
Behavioral Interview - that's easy, you have to talk about instances that may have come up in your career or you should be smart enough to make one and speak just like Extempore.