• A psychologist wants to estimate the proportion of people in a population with IQ scores between 80 and 140. The IQ scores of this population are normally distributed with a mean of 110 and a standard deviation of 15. Use the Empirical Rule to estimate the proportion.
• The mean of a normally distributed data set is 110, and the standard deviation is 15. a) Use the standard normal table to find the probability that a randomly-selected data value is greater than 95. b) Use the standard normal table to find the probability that a randomly-selected data value is greater than 125.
• A psychologist wants to estimate the proportion of people in a population with IQ scores between 80 and 140. The IQ scores of this population are normally distributed with a mean of 110 and a standard deviation of 15. Use the standard normal table to estimate the proportion.
• Why are your answers to questions 8 and 9 not identical to your answers to questions 6 and 7, respectively?
• The mean of a normally distributed data set is 118, and the standard deviation is 16. a) Use the standard normal table to find the probability that a randomly-selected data value is greater than 140. b) Use the standard normal table to find the probability that a randomly-selected data value is less than 90.