A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6, 3.8, 4.0, and 3.9.For 0.01 level of significance,what is the cut-off weight in ounces?

THe answer is 3.71... and Please explain to me why the answer is 3.71.. Thank you