Sampling

             To obtain our sample, we first took all four lists (freshman, sophomore, junior, and senior classes), and we then put all the data into Minitab.  Then we used the Minitab Random Data- Sample from Column to obtain a simple random sample of 160 students from the entire population of students at North Olmsted High School.  The population of interest in our study is all of the students currently enrolled at North Olmsted High School.  There is 1, 603 students in the school and we printed 160 surveys to send out to the random students selected by the random number generator in Minitab.  Our survey looked like the following:

 

1. What was your 3^rd Quarter (Quarter only, not cumulative) G.P.A. this year?

a)      0 - 0.999          b) 1 - 1.999      c) 2 - 2.999      d) 3 - 3.999  e) 4 – 5

 

2. What is your natural hair color?

a)      black               b) brown          c) blonde        d) red

Please return this As Soon as Possible.

 

            After printing the surveys, we went to the guidance office and obtained the files of every schedule of a student at North Olmsted High School.  We went through each name to find that person’s first period teacher.  If that student was at Polaris or PSOP, we used a different class period, depending on their time at the high school.  After getting all 160 student’s teachers and class periods, we turned the surveys into Mrs. Caso, so that they could be sent out to the teachers.

            From our survey we got back 127 surveys.  The raw data and graphs of the data from these surveys are included in the following links.

     

 

The following is the chi-square test we did on our data:

Ho: the mean GPA for all hair colors is the same

Ha: the mean GPA for the different hair colors is not the same

alpha: .05

We must assume that the samples are random and independently chosen.  The following table shows the expected values for each category.

	A	B	C	D	E	Total
Black	0	4	1	5	2	12
Blonde	0	2	7	15	3	27
Brown	1	6	26	40	10	83
Red	0	0	0	2	2	4
All	1	12	34	62	17	126

Since there are multiple expected values that are less than five, we cannot come to any valid conclusion.