u do not need to know the formula for any test
they will give the formula in the question
all u need to know is wen to use which and wen to use alternate and nulll hypothesis
By the way do u know how to do q2d from the sample paper for unit6?
see the table u drew in Q2(a)and find out the greatest and smallest change for each bar.
plot these points of each bar in the graph and join the points with ruled line, so u have 2 range bars, one for regular caffiene and other for non caffiene drinks.
N.B. I think the line must pass through the centre of the bar.