The measurements of the nominal shear strength (in kN) for a sample of 15 prestressed concrete beams are as follows:
580 400 428 825 850 875 920 550 575 750 636 360 590 735 950
* Data from Tan, k., K. tong, and C. Tang. 2001. Direct strut-and-tie model for pre-stressed deep beam. Journal of Structural Engineering, 2001:1076-1084.
(a) Check that the nominal shear strength measurements are normally distributed and verify that there are no outliers in the sample data.
(b) Can you support the claim that the mean nominal shear strength is actually less than 600 kN at ? = 0.05? Find the p-value.
(c) Compute the power of the test if the true mean nominal shear strength is 750 kN.