Effect of one low and one high value on the median, and two unknown values from the new mean and range

A sports club has \(25\) members. In a fitness test, \(23\) of the members each record the number of sit-ups they complete in one minute. Two members, Wei Ling and Haziq, are away on the day of the test. The box-and-whisker diagram below summarises the \(23\) results.

Later, Wei Ling and Haziq also take the test. Wei Ling completes fewer than \(12\) sit-ups and Haziq completes more than \(30\) sit-ups.

1. Explain why the median of all \(25\) results is still \(19\).[1]

The mean of the original \(23\) results is \(20\). For all \(25\) results, the mean is \(20.4\) and the range is \(28\).

2. Find the number of sit-ups completed by Wei Ling and the number completed by Haziq.[5]