Study
Sampling Technique
Our population of interest were the students at NOHS, so, we first obtained a master list of all students at NOHS from Mrs. Caso. Using MINITAB (Calc->Random Data->Sample From Columns), we randomized 150 students from the list. Of the 150 students randomized, 72 were female and 78 were male. Additionally, our original sample contained 39 freshmen, 35 sophomores, 42 juniors, and 34 seniors. From the surveys we received back, we counted 45 females and 49 males, resulting in a total of 94 valid surveys. We also received 1 invalid survey (more than one answer was chosen for both questions) and 6 blank surveys.
Sample Survey
PBHZ
Please only fill in one square for each question.
What car color do you prefer?
[] Silver/White [] Black [] Blue [] Other
What’s your gender?
[] Male [] Female
Significance Test
Type of Test:
We used "Cross Tabulation and Chi-Square" of MINITAB in order to perform a test of independence because we are attempting to observe if there is an association between gender and car color preference.
Check for Assumptions:
1. Expected cell counts above 5.
2. Random sample.
Significance Test:
Null hypothesis: There is no association between gender and car color preference; the two variables are independent.
Alternative hypothesis: There is an association between gender and car color preference; the two variables aren't independent.
Alpha: 0.05
Test Statistic:
12.93 13.40 10.53 8.14 45.00
14.07 14.60 11.47 8.86 49.00
27.00 28.00 22.00 17.00 94.00
Expected count
Likelihood Ratio Chi-Square = 6.470, DF = 3, P-Value = 0.091
X² = 6.380
P-Value = 0.095