A random sample of size 16 from a normal distribution with = 3 produced a sample mean of 4.5. a) Is the distribution normal? Explain. _____________________________________________ _____________________________________________________________________________. b) Compute the sample test statistic z under the null hypothesis 0: = 6.3 c) For : < 6.3, find the critical value for = 0.01. d) For a level of significance of 0.01 and the hypotheses of parts (b) and (c), do you reject or fail to reject the null hypothesis? Explain