To estimate the probability that a randomly selected person has an IQ between 90 and 110 in the Stanford-Binet IQ Test, we can use the empirical rule, which states that for a normal distribution: 1. Approximately 68% of the data falls within one standard deviation from the mean. 2. Approximately 95% of the data falls within two standard deviations from the mean. 3. Approximately 99.7% of the data falls within three standard deviations from the mean. In this case, the mean is 100 and the standard deviation is 20. Since the given IQ range of 90-110 falls within the first standard deviation from the mean, we can use the empirical rule to estimate that the probability is approximately 68%.