Question

The inlet pressure of a steam generator is to be held constant at 5.00 MPa. During the test, the inlet pressure was measured 120 times. The resolution of the digital pressure gauge used was 0.001 MPa. The number of results, m, is the number of readings falling in an interval of ±0.04 MPa centered about the listed pressure.

Pressure, p, in MPa	Number of Results, m
4.960	4
4.970	6
4.980	6
4.990	35
5.000	45
5.010	14
5.020	5
5.030	4
5.040	1

a)     a) Find the mean and standard deviation of the given pressure data.

b) b)  Determine 95% confidence interval for the calculated mean pressure.

c) Conduct a hypothesis testing if the data obtained indicate a target pressure of 5.00 MPa at a confidence level of 99

Answer 1

Graphs are drawn for all the 120 readings using Minitab software. Mean and standard deviation are 4.9966 and 0.014465 as shown in the figure below with an arrow diagram

Also, the 95 % Confidence interval is calculated as (4.9940,4.9992) shown in below figure with an arrow

Hypothesis testing has been done using Minitab software for the data provided with a 99 percent confidence interval shown in the below graph

Here p-value(0.011) greater than 0.01 indicates that the mean is not significantly different than the target(5 MPa) with 99 % CI