Discussion:
Q: Does bread lose its vitamins when stored? Small loaves of bread were prepared with flour that was fortified with a fixed amount of vitamins. After baking, the vitamin C content of two loaves was measured. Another two loaves were baked at the same time, stored for three days and then the vitamin C content was measured. The units are milligrams per hundred grams of flour (mg/100g). Here are the data:
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Immediately after baking:
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47.62
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49.79
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Three days after baking:
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21.25
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22.34
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a). When bread is stored, does it lose vitamin C? To answer this question, perform a two-sample t test for these data. Be sure to state your hypotheses, the test statistic with degrees of freedom, and the P-value.
b). Give a 90% confidence interval for the amount of vitamin C lost.