Question 1105771
This should be a one-tailed t-test, because a sample is taken and the sd of the sample is used to estimate the variance.  One-tail may be done, because the expectation will be the delay should be shorter.

Ho: delay is same or worse
Ha: delay is less
alpha=0.05, critical value is t 0.95 df=4=-2.132
t=(15.2-20)/6.3/sqrt(5)
t=-4.8*sqrt(5)/6.3=-1.70
p-value=0.08
There is insignificant evidence to say that the mean time delay is less.