1. Berta samples the IQ scores of 100 third graders. She calculates the standard deviation and obtains a result of –14.5. Based on this result, we can say with certainty that

a. The sample included many extremely low IQ scores.

b. The distribution of IQ scores was negatively skewed.

c. Berta made a mistake when she calculated the standard deviation.

d. The distribution had a very small range.

2. A math achievement test was administered to students in two elementary schools. A summary of the results is given below.

School A: Mean = 50, Standard Deviation = 10
School B: Mean = 60, Standard Deviation = 10

Based on these results, we can say with certainty that

a. The two distributions have the same range.

b. The two distributions have the same variance.

c. The scores in School B are more variable than the scores in School A.

d. All the School A scores are between 40 and 60, and all the School B scores are between 50 and 70.

3. A reading achievement test was administered to students in two elementary schools. A summary of the results is given below.

School A: Mean = 45, Variance = 64
School B: Mean = 45, Variance = 81

Based on these results, we can say with certainty that

a. More students scored above the mean in School B than in School A.

b. All the School A scores are between 37 and 53, and all the School B scores are between 36 and 54.

c. The two distributions have the same range.

d. The two distributions have different standard deviations.