Final answer:
The trend of increasing average IQ scores at Bradbury High over the past 50 years is consistent with the Flynn effect. The discussion of the probability that a group of 20 adults will have an average IQ between 85 and 125 falls under the distribution of IQ scores and the use of statistical concepts like standard deviation and the bell curve.
Step-by-step explanation:
The increasing average IQ scores over the past 50 years at Bradbury High is consistent with a phenomenon known as the Flynn effect, which is the observation that IQ scores have been increasing with each generation worldwide. Several factors may contribute to this effect, including improvements in education, nutrition, healthcare, and access to information.
Discussing the probability of 20 randomly selected adults having an average IQ score between 85 and 125 involves understanding the distribution of IQ scores and the use of statistical concepts such as the standard deviation and the central limit theorem. Since we know that the average adult IQ score is 105 with a standard deviation of 20, we can deduce that an IQ score between 85 and 125 is within one standard deviation of the mean, and this is where we expect to find the majority of individual IQ scores, based on the bell curve.
When evaluating IQ scores, for example, one that falls within one standard deviation above or below the mean (between 85 and 115) is considered average. An IQ score of 130 or above is generally considered a superior level, while a score of 70 or below may indicate an intellectual disability.