The fоllоwing dаtа set cоntаins the results of a Wagner turbidity test performed on 15 samples of standard Ottawa testing sand (in microamperes): 24.2, 26.5, 25.6, 27.2, 26.4, 27.0, 22.8, 24.3, 27.4, 25.7, 23.9, 23.3, 25.5, 28.2, 24.0 The summary information is as follows: