M&M Lab

Concepts of Chi-Square distributions and "Goodness of Fit" test using M&M's
By: Aidan, Brett, Chelsey, My-Linh

In 1995, the M&M manufactuer's company claims that on average a new mis of colors of m&m's plain chocolate candies will contain 30% Browns, 20% yellows and reds, and 10% of oranges, greens, and blues. This has been know change every few years. Our task is to see if the current mix of m&m's matches that of the company's claim. It has also been known that the smaller packages we will use vary more than normal size packages.

In order to test this claim we will use a Chi-Square "Goodness of fit" Test.

First we divided the colors up in our group with the four smaller packages of M&M's we used. Next we recorded our counts of blue, green, red, yellow, brown,and orange and the expected values of these colors based on the company's claim on the chart below.

GRAND TOTAL: 86

ASSUMPTIONS: All E's exceed 5


H0 : The population proportion of M&M's are equal to those claimed by the manufacturer

Ha : They are not equal

On the Calculator.....
Enter observed values in chart into ---L1
Enter expected values in chart into ---L2
Enter ((O-E)^2)/E values into---L3

CONCLUSION:
We reject the null since pvalue less than alpha=.05.
There is statistical evidence to suggest that the population proportions of M&M colors is not equal to the manufacturers claim.