(a(i)(a))[1]
Use the cumulative frequency diagram to estimate the median.
(a(i)(b))[2]
Use the cumulative frequency diagram to estimate the interquartile range.
(a(ii))[2]
One motorist is chosen at random. Find the probability that this motorist travels more than 1800 km.
(b)[3]
Calculate the car's average speed. Give your answer in km/h.
(c(i))[1]
Show that the number of cars with a top speed in the interval $120 < v \leq 160$ is 8.
(c(ii))[6]
Calculate an estimate for the mean top speed. Show all your working.