The average heat output of chemical heating pads, according to the manufacturer, is 45 watts. The sampling mean for a group of 12 pads is 23.4 watts. Assume that the standard deviation is 9.4 watts,...

The average heat output of chemical heating pads, according to the manufacturer, is 45 watts. The sampling mean for a group of 12 pads is 23.4 watts. Assume that the standard deviation is 9.4 watts, as determined by prior experiments.

a) Is there any proof that the average heat production is larger than 45 watts? Formally test the hypothesis with a 6% significance threshold.

b) What is the significance level for this test?