Nellie is preparing for the 100 metres for her school athletics team. The times below are in seconds and were recorded during training over a three-week period. We list them here in increasing order rather than sequential order.

19.2; 20.9; 21.2; 21.3; 21.3; 21.3; 21.4; 21.4; 21.4; 21.5; 21.5; 21.5; 21.5; 21.5; 21.5; 21.6; 21.6; 22.0; 22.5; 23.8.

Her coach and the school principal both looked at these figures and made the following comments.

Coach: "The Inter-School 100 metre record for Nellie’s age group is 20.5 seconds. There’s no doubt in my mind that when the Inter-School’s meet takes place in two weeks time, Nellie will come close to breaking that record."

Principal: "I am very impressed with Nellie. She has done well in the 100 metres since she started at this school three years ago. Her time of 19.2 seconds says that when she is really trying she can be world class. The fact that most of her times are clustered around 21.6 seconds tells me that she doesn’t try hard enough at training."