Flavor and Statistical Inference Course

1. A statistics professor has just given a final examination in his statistical inference course. He is particularly interested in learning how his class of 40 students performed on this exam. The scores are shown below.

77 81 74 77 79 73 80 85 86 73

83 84 81 73 75 91 76 77 95 76

90 85 92 84 81 64 75 90 78 78

82 78 86 86 82 70 76 78 72 93

What is the mean score on this exam?

ANSWER:

Mean = 78.40, Median = 77.50

2. In February 2002 the Argentine peso lost 70% of its value compared to the United States dollar. This devaluation drastically raised the price of imported products. According to a survey conducted by AC Nielsen in April 2002, 68% of the consumers in Argentina were buying fewer products than before the devaluation, 24% were buying the same number of products, and 8% were buying more products. Furthermore, in a trend toward purchasing less-expensive brands, 88% indicated that they had changed the brands they purchased. Suppose the following complete set of results were reported. Use the following data to answer this question.

| |Number of Products Purchased | |
|Brands Purchased |Fewer |Same |More |Total |
|Same |10 |14 |24 |48 |
|Changed |262 |82 |8 |352 |
|Total |272 |96 |32 |400 |

What is the probability that a consumer selected at random purchased fewer products than before?

0.6800