Answer:
a.
b.
c.
Attached file
d.
Apparently the practice of smoking reduces the ability to fall asleep, demanding much more time in individuals who smoke, than in those who do not smoke.
Step-by-step explanation:
a, b) For the group of smoking individuals, the average time it takes to fall asleep and the standard deviation of those times is:
a, b) For the group of non-smoking individuals, the average time it takes to fall asleep and the standard deviation of those times is:
c. In the attached file you can see the diagram of points for the times, in the smoking and non-smoking groups.
d. Apparently the practice of smoking reduces the ability to fall asleep, demanding much more time in individuals who smoke, than in those who do not smoke.