The level of dissolved oxygen in a river is an important indicator of the water’s ability to support aquatic life. You collect water samples at 15 randomly chosen locations along a stream and measure the dissolved oxygen. Here are your results in milligrams per liter:

4.53, 5.04, 3.29, 5.23, 4.13, 5.50, 4.83, 4.40, 5.42, 6.38, 4.01, 4.66, 2.87, 5.73, 5.55

​Construct a 95% confidence interval for the mean dissolved oxygen level for this stream. Follow 

​the Inference Toolbox.