$3 Problem 1-20 Marks Fishing industry is an important aspect of economy for communities stretching alongside the lakes. The productivity of fishing depends on the speed of the boats which in turn is due to the rotational speed of their propellers which are determined to be normally distributed random variables. We sampled the speed of 21 randomly and independently chosen boats with a sample mean x = 101 rpm and a sample standard deviation of S= 19 rpm. a) Test the hypothesis of the true mean of propeller speed Ha: H = 100 versus: Hj: /