Cola makers test new recipes for loss of sweetness during storage. Trained tasters rate the sweetness before and after storage. Here are the sweetness losses (sweetness before storage minus sweetness after storage) found by 10 tasters for one new cola recipe:
2.0 0.4 0.7 2.0 -0.4 2.2 -1.3 1.2 1.1 2.3
Take the data from these 10 carefully trained tasters as an SRS from a large population of all trained tasters.
(a) Use these data to see if there is good evidence that the cola lost sweetness.
(b) It is not uncommon to see the t procedures used for data like these. However, you should regard the results as only rough approximations. Why?