Another Confidence Interval Qn!

How do I do this?

It is claimed that a new treatment for prolonging the lives of cancer patients is more effective
than the standard one. The mean survival period for patients on the standard treatment is 4.3
The new treatment is administered to 20 patients and their survival times are recorded and
summarized below:
n x s se(x)
20 4.9 1.1 0.25
(a) Is there statistical evidence that taking the new treatment improves survival time? Show
all calculations clearly and give a concise conclusion.
(b) Calculate a 95% confidence interval for the mean survival time (after taking the new
(c) Explain the relationship between (a) and (b), with specific reference to this problem.