Assignment: Coffee Research
At the beginning of the semester in September, Mindawanted to study the coffee consumption in her dorm building, so she randomly interviewed 44 students (including 25 male students and 19 female students) in her dorm building and asked how many cups of coffee they drink per day. Till the end of the semester, she suspected that during the final exam period, the students would drink more coffee to keep them stay up late for preparation for the exams. So she called those 44 students again 2 days before the final exams in December, and asked them how many cups of coffee they had per day during the final exam period. The data is attached at end.
1. Get the 95% confidence interval of the mean cup of coffee the students in her dorm building drink per day at the beginning of the semester
2. Formulate the hypothesis test using significance level 0.05 to check whether the data support Minda's claim that students would drink more coffee to keep them stay up late for the exams.
3. Regarding the changes of average cups of coffee consumed from the beginning to the end of the semester, is there any difference between female and male students? Formulate your hypothesis and test it.
After analysis before, briefly answer
1. What is the sample and what is the population in this study? What is the parameter(s) that Minda is interested in?
2. Do you think Minda's data collection method is good in general? If you were going to give advises on the data collection method, what would be your suggestions?
3. What assumptions did you make in the analysis?
Table: Number of cups of coffee of students from Minda's dorm building
|
Student
|
Gender
|
September
|
November
|
|
1
|
female
|
1
|
3
|
|
2
|
female
|
2
|
3
|
|
3
|
male
|
2
|
3
|
|
4
|
male
|
2
|
4
|
|
5
|
female
|
4
|
2
|
|
6
|
male
|
2
|
3
|
|
7
|
male
|
3
|
4
|
|
8
|
female
|
2
|
3
|
|
9
|
male
|
4
|
3
|
|
10
|
male
|
1
|
2
|
|
11
|
male
|
3
|
3
|
|
12
|
female
|
2
|
4
|
|
13
|
male
|
1
|
3
|
|
14
|
female
|
2
|
5
|
|
15
|
male
|
2
|
4
|
|
16
|
male
|
1
|
3
|
|
17
|
female
|
2
|
4
|
|
18
|
male
|
3
|
4
|
|
19
|
male
|
3
|
3
|
|
20
|
female
|
2
|
2
|
|
21
|
male
|
3
|
2
|
|
22
|
male
|
2
|
2
|
|
23
|
female
|
1
|
2
|
|
24
|
female
|
1
|
2
|
|
25
|
female
|
2
|
2
|
|
26
|
male
|
3
|
4
|
|
27
|
female
|
3
|
2
|
|
28
|
female
|
1
|
4
|
|
29
|
male
|
2
|
4
|
|
30
|
female
|
1
|
2
|
|
31
|
female
|
1
|
2
|
|
32
|
male
|
1
|
2
|
|
33
|
female
|
2
|
3
|
|
34
|
male
|
3
|
5
|
|
35
|
female
|
2
|
4
|
|
36
|
male
|
1
|
4
|
|
37
|
female
|
3
|
3
|
|
38
|
male
|
1
|
3
|
|
39
|
female
|
2
|
3
|
|
40
|
male
|
2
|
4
|
|
41
|
male
|
4
|
4
|
|
42
|
male
|
3
|
3
|
|
43
|
male
|
2
|
2
|
|
44
|
male
|
2
|
2
|