Abstract
Overview of The Study
We started our study by looking for
similar studies conducted in the past using the search engine Google. By typing “M&M proportion studies” into Google, we found several different studies that tested the proportions of M&Ms to those stated by the M&M Company. We were able to make use of these previous studies as a base for our own study.
Then, we obtained our sample, 80 1.69 oz. bags of M&Ms from Gordan’s Food Service, which contained a total of 4436 M&Ms. Our population of interest was all M&Ms made after the proportions from the company were last adjusted.
After obtaining the 80 bags, we counted each bag
individually and noted the number of M&Ms of each color
in each bag. Then, we inserted our data into Minitab and
calculated the proportion of each color in each bag.
Next, we ran our four tests comparing individual
proportions. In the first test, we wanted to determine
whether the proportion of blue M&Ms in a bag is greater
than the proportion of orange M&Ms in a bag. In the
second test, we wanted to determine whether the
proportion of red M&Ms in a bag is less than the
proportion of blue M&Ms in a bag. In our third test, we
wanted to determine whether the proportion of brown M&Ms
in a bag is different than the proportion of green M&Ms
in a bag. In our final test, we carried out a Chi-Square
test to determine whether the proportions reported by
the Mars Company differ from the actual propotions.
After performing each test, we concluded that the true
proportion of blue M&Ms is not
significantly greater than the true proportion of orange
M&Ms per bag, that the true proportion of red M&Ms is
significantly less than the true proportion of blue M&Ms
per bag, that the true proportion of green M&Ms is
significantly different than the true proportion of
brown M&Ms per bag, and that at least one of the
proportions significantly differs from
the proportions stated by the M&M company. Also, the
graphs of each color's proportion per bag were
approximately normally distributed. While performing the
study, we found some weaknesses such as the fact that
the proportions for each color may have been readjusted
over time and that the bags came from two different
boxes. Lastly, we concluded that our data can be
extrapolated for the time period during which the
proportions were the same.