Question 1102481
At the 0.05 level of significance, 
test statistic is z=(xbar-mean)/sigma/sqrt(n)=(5.2-5)/1.56/sqrt (64)
This is z=0.2*8/1.56=1.03.  This has a p-value of 0.15 which is greater than alpha of 0.05, so fail to reject Ho and b. is the answer.


If one uses a two-sided test, the 95% CI half interval is 1.96*1.56/8, z*sigma/sqrt(n), using a z test because the population sd is used.  That half-interval is 0.38, so the 95% CI is [4.82, 5.58].
The appropriate decisions is b., do not reject Ho.  The 95% CI contains the null hypothesis, and that means the null hypothesis is not rejected.