CRAZY CORE SKITTLES By Rachel Collins

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CRAZY CORE SKITTLES By Rachel Collins
2
The Purpose

• It is stated that the Crazy Cores Skittles
  Company have 56.7 grams of Skittles in each bag.
  Is this accurate?
• The population of interest is a sample size of 15
  regular sized Crazy Core Skittles bags from a
  private supplier.

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Sneaky Lurking Variables

• The Skittles weighed in the experiment all came
  from one supplier, so there is a possibility that
  the skittles all came from the same batch from
  manufacturer.
• The supplier from which produced the skittles
  does not have a license to sell, so there can be
  some doubt if the goods he/she were selling are
  standard.

4
More Luring Variables

• The efficiency of the scale is questioned due to
  the fact that I carried it around in my purse.
• My sample size is only 15, while it is large
  enough to perform a one sample T test, if there
  was a larger sample it would be able to speak for
  a larger amount of skittles.

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Procedure

• Contact the skittles dealer.
• Weigh each bag of skittles and record the weight.
  

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Numbers, Graphs, and Data

• Skittles Weight
• 60.1, 59.01, 59.3, 58.4 ,58.4, 59.5 ,58.6 ,62.1
  ,61.9 ,57.8, 59.4 ,60.9 ,58.24 ,57.6 ,56.2

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More Numbers

• Five number Summary
• Mean 59.16 grams
• Minimum 56.2 grams
• Maximum 62.1 grams
• Q1 58.24 grams
• Q3 60.1 grams
• Sx 1.59
• Medium59.01 since the mean is greater than the
  medium, the graph is slightly skewed to the
  right.

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Hypothesis

• Ho In a sample size of 15 bags of Crazy Core
  Skittles, the mean weight is 56.7 grams. X
  56.7grams
• Ha In a sample size of 15 bags of Crazy Core
  Skittles, the mean weight is more than 56.7 grams
  Xgt56.7 grams

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Inference Procedure

• The significance level that the data will be
  tested is at .05.
• The sample size is fifteen 56.7 gram Crazy Core
  Skittle bags.
• A one sample T test will be used since the
  population mean is unknown.

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Conditions

• Not an SRS PROCEED With Caution
• Sample size shows little to no skewness and no
  extreme outliers.

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Box Plot
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Formulas

• T test
• T x-µ
• s/n df n-1
• X59.13 µ56.7 S1.59 n15
• 59.13-56.7 5.979 T5.979 P value
  1.63e-5
• 1.59/15

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What Does The Numbers Mean?

• Conclusion

• The P- Value was 1.63e-5 at an Alpha level of
  .05. This is significant evidence to reject the
  null Hypothesis.
• Therefore, In a sample size of 15 bags of Crazy
  Core Skittles, the mean weight is more than 56.7
  grams. Xgt56.7 grams

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Confidence Interval Test

• Confidence Interval for
• X59.133 T5.979 n15 S1.59
• 59.133/-5.979 15-1 (1.59/v15 58.28, 60.047

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Confidence Conclusion

• According to the Confidence Interval test, I am
  95 confident that the mean weight of Crazy Core
  Skittles bags lays between 58.28 grams and 60.047
  grams. This supports my rejection of my null
  hypothesis.

16
Reflection

• My project shows me that in a population of 15
  Crazy Core Skittles bags, the mean weight is
  more than what is stated on the bag.
• Some of the weakness of the project were that the
  data did not come from an SRS.