In order to measure the effectiveness of a new procedure for pruning grapes, 15 workers are assigned to prune an acre of grapes. The effectiveness is measured in worker-hours per acre for each person.
5.2 5.0 4.8 4.5 3.9 6.1 4.2 4.4 5.5 5.8
4.2 5.3 4.9 4.7 4.9
Obtain a 99% con?dence interval for the median time required to prune an acre of grapes for this procedure and interpret its meaning.