A large internet retailer is studying the lead time (elapsed time between the time when the order is placed and the time it is filed). The table below gives the lead times (in days) for a random sample of recent orders.
14 19 5 13 20 15 9 16
20 9 2 10 7 12 18 24
1 8 11 5 13 6 2 11
16 20 18 2 4 10 22 17
13 10 21 12 23 18 10 3
1. Display the above data in a group frequency distribution using five (5) classes of equal width.
2. With the aid of an appropriate, graph drawn to scale, determine the mean, the 80% percentile and the mid-50% range.
3. Calculate the standard deviation and hence estimate the CV using the mean obtained in 1.2. Interpret your result.