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Are Skittles Evenly Distributed?. BY: Kristin Taylor. Introduction & Research Question. Question- Are the flavors in a 2.17 oz. bag of original Skittles evenly distributed? Population of interest- 5 bags of 2.17 ounce original Skittles. Procedure. Pour one bag of Skittles onto a paper towel
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Are Skittles Evenly Distributed? BY: Kristin Taylor
Introduction & Research Question • Question- Are the flavors in a 2.17 oz. bag of original Skittles evenly distributed? • Population of interest- 5 bags of 2.17 ounce original Skittles
Procedure • Pour one bag of Skittles onto a paper towel • Sort the Skittles by color • Count the # of each color and record • Calculate total # of Skittles in individual bag • Place skittles in a cup/bowl • Repeat steps 1-5 for the remaining 4 bags
Intro & Research (cont.) Weakness Strength • The population size could have been larger • The number of each color of Skittles could have been miscalculated, which would have skewed the sum in the bag • The experiment setup • The Skittles were all the same size • No half pieces
Data Collection • Data collected by: • Sorting the colors in a 2.17 oz. bag of Original Skittles • Counting them & recording the total of each color • Add up all the totals to get the total amount of Skittles in the bag • Then divide the # of each color by the total # of Skittles to get the percentage EX. 11/58 = .189 ≈ 19%
I am confident that my sample represents the population because the total number of Skittles within the five bags were around the same total. The total ranged from 58-61. Therefore, I am confident that if a larger sample size was used then the total amount of Skittles would be within this range. Using the z-interval test on a TI-83, I’m 90% confident that the total amount of Skittles in a 2.17 0z. bag would range from 55-65 Skittles.
Cumulative Average The graph to the right shows the sum of each color within the sample population 5-number summary: Min- 51 Mean: 59.8 Q1- 52 σ: 6.62 Med- 62 Q3- 66.5 Max- 67 Shape: the graph is roughly symmetric Outliers: there are no outliers Center: 62 Spread:51- 67
Inference Procedure • Null Hypothesis- The flavors of Original Skittles in a 2.17 oz. bag are evenly distributed. • Alternative Hypothesis- The flavors of Original Skittles in a 2.17 oz. bag are not evenly distributed. • Significance level: α =.05 • Sample size: 5 bags of 2.17 oz. Skittles
Chi-square Test Ho: The flavors of Original Skittles in a 2.17 oz. bag are evenly distributed. Ha: The color of Original Skittles in a 2.17 oz. bag are not evenly distributed.
Step 2: The χ² GOF Test will be used • Check Conditions: • The data does not come from a SRS therefore, I may not be able to generalize about the population • The expected numbers are greater than 5 Step 3: Χ² = ∑(O-E)² E = (66-59.8)² + (67-59.8)² + (51-59.8)² + (62-59.8)² + (53-59.8)² 59.8 59.8 59.8 59.8 59.8 = 3.66
Step 4: Using a TI-84, the p-value was 0.45 There is strong evidence to reject the null hypothesis at the α= .05 level because the p-value is greater than .05 (.45 ≥ .05). Therefore, the flavors in a 2.17 oz. bag of Original Skittles arenot evenly distributed, which can be seen in the graphical displays of each individual bag. From reviewing my graphical displays and charts I noticed that within four of the bags of Skittles only two of the colors within the bag had equal amounts.