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.
Well you have to find out how many cd is 40% and 30%
30% = 30x.3=9
40% = 30x.4=16
now add 16 and 9
16+9=25 now subtract 25 from 30 and see that you have 5 cd of a different type of music to find that as a % divide 5 by 35 to get .14 I rounded it to the nearest hundreth now move the decimal over 2 spots to get 14%