__Chocolate statistics__

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**Initial observations**

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Look at your chocolates. Which do you think has the greater mass, a Smartie or an M&M? Or do you think they have the same mass?

Now touch your chocolates and ask yourself the same question.

Create a Hypothesis 1 (H_{1})_{ }and a Null Hypothesis (H_{0 })

**Data Collection**

How many Smarties/ M&Ms do you think you would need to measure the mass of to collect enough data to be sure of your answer?

Measure the mass of your Smarties. Now do the same for your M&Ms.

Record the data in an appropriate table. Don’t forget to include the units and the uncertainties of your equipment.

**Data Processing**

Calculate the arithmetic mean mass for your Smarties.

Now do the same for your M&Ms.

Calculate the Standard Deviations.

Perform an unpaired t-test on your results.

**Data Presentation**

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Draw a graph of your results. Include error bars.

**Conclusion and Evaluation**

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Which hypothesis can you accept/reject and why?

What were the possible errors in your experiment?

**Calculating Standard Deviation**

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The Standard deviation (SD, s or ) of the mean tells us how spread out the reading are ( the ‘spreadoutness’ of the data).

1. Calculate the mean

2. Measure the deviations

3. Square the deviations

4. Add the squared deviations

5. Divide by the number of samples minus 1

6. Square root the answer

Ask your math teacher to show you how to calculate the standard deviation on your calculator. Or…. Just use Excel :)

**The unpaired t-test**

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Go to

http://www.graphpad.com/quickcalcs/ttest1.cfm

and enter your data.

Your analysis is due by the end of class on Friday.

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