A CTI student is interested in comparing the programming skill of SE and 
CS graduate students. His colleagues argue that both groups, on average, 
have the same skill level but the student believes that SE students can 
develop "working" software more quickly.

The student decides to focus on students who have completed both the pre-
requisite and core phases. He selects random samples from each group and 
asks them to participate in a non-trivial programming assignment. He 
provides assignments to 40 CS and 35 SE students and records the time that 
each student takes to code and debug the program. He discovers that the 
mean time for CS students is 5.0 hours with standard deviation 1.1 
hour and for SE students the mean is 4.6 hours with standard deviation 
1.08 hours.

a) Conduct a test of hypotheses.
b) Given your findings, is a point estimate appropriate? If so,
   provide a point estimate of the difference in average coding time
   as well as a 90% CI.