The accompanying data on cube compressive strength (MPa) of concrete specimens appeared...

The accompanying data on cube compressive strength (MPa) of concrete specimens appeared in the article “Experimental Study of Recycled Rubber-Filled High- Strength Concrete” (Magazine of Concrete Res., 2009: 549–556):

a. Is it plausible that the compressive strength for this type of concrete is normally distributed?

b. Suppose the concrete will be used for a particular application unless there is strong evidence that true average strength is less than 100 MPa. Should the concrete be used? Carry out a test of appropriate hypotheses using the P-value method.