Question

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 mu equals 8.4 psi. Due to changes in the manufacturing​ process, the​ quality-control manager feels that the average pressure has increased. The null hypothesis was rejected. Choose the correct answer below.

A. There is not sufficient evidence that the mean of the pressure required to open a certain valve has not changed.
B. There is not sufficient evidence that the mean of the pressure required to open a certain valve has increased.
C. The mean of the pressure has not changed.
D. The mean of the pressure has increased.
E. There is sufficient evidence that the mean of the pressure required to open a certain valve has increased.
F. There is sufficient evidence that the mean of the pressure required to open a certain valve has not changed.

Answer 1

option E is correct,which states that there is no sufficient evidence that the mean of the pressure is required to open a certain valve was increased.

Answer 2

E. There is sufficient evidence that the mean of the pressure required to open a certain valve has increased.

Explanation:

Null hypothesis(H0): μ= 8.4 psi

Alternative hypothesis (H1): μ> 8.4 psi

If the test was due with a representative minimum number of observations. And, if the null hypothesis was rejected, then the mean pressure required to open a valve is greater than 8.4 psi. We can conclude that (at a certain level of confidence) there is sufficient evidence that the mean of the pressure required to open a certain valve has increased.