(a(i))[1]
Find the range of the data.
(a(ii))[3]
Calculate the mean value.
(a(iii))[2]
Find the probability that a customer chosen at random buys more than 4 items.
(b(i))[2]
Complete this statement about the value of $l$.
(b(ii))[5]
Calculate the number of complete revolutions that a wheel makes during this journey.