A quality control experiment is to be done on a machine that fills tubes with toothpaste. Its specifications require that it fill tubes with 4.7 oz. A random sample of 40 tubes filled by machine is taken and each tube is weighed. The resulting data are below, with the weight of the tube already having been subtracted from each. 

4.66, 4.61, 4.71, 4.63, 4.70, 4.62, 4.63, 4.61, 4.70, 4.56 4.60, 4.66, 4.68, 4.57, 4.67, 4.72, 4.67, 4.64, 4.66, 4.75 4.69, 4.64, 4.67, 4.65, 4.69, 4.65, 4.75, 4.53, 4.57, 4.74 4.68, 4.67, 4.66, 4.68, 4.64, 4.65, 4.64, 4.80, 4.71, 4.69.

 Perform a hypothesis test at the 90% confidence level to determine if the machine is performing according to specifications.