Question 12 (1 point) State the conclusion based on the results of the test. The mean of the pressure required to open a certain valve is known to be u=7.8 psi. Due to changes in the manufacturing process, the qualitycontrol manager feels that the average pressure has increased. The null hypothESiS was not rejected. Choose the correct answer below. 0 The mean of the pressure has increased. 0 The mean of the pressure has not changed. 0 There is sufficient evidence that the mean of the pressure required to open a certain valve has not changed. 0 There is not sufficient evidence that the mean of the pressure required to open a certain valve has increased. Q There is not sufficient evidence that the mean of the pressure required to open a certain valve has not changed. 0 There is sufficient evidence that the mean of the pressure required to open a certain valve has increased