1.You may need to use the appropriateappendix tableortechnologyto answer this question.

IQ scores (as measured by the Stanford-Binet intelligence test) in a certain country are normally distributed with a mean of80and a standard deviation of20. Find the approximate number of people in the country (assuming a total population of 323,000,000) with an IQ higher than126. (Round your answer to the nearest hundred thousand.)

_______people

2.This exercise uses the normal probability density function and requires the use of either technology or a table of values of the standard normal distribution.

The cash operating expenses of the regional phone companies during the first half of 1994 were distributed about a mean of$29.78per access line per month, with a standard deviation of$2.25. Company A's operating expenses were$27.00per access line per month. Assuming a normal distribution of operating expenses, estimate the percentage of regional phone companies whose operating expenses were closer to the mean than the operating expenses of Company A were to the mean. (Round your answer to two decimal places.)

_________%

3.This exercise uses the normal probability density function and requires the use of either technology or a table of values of the standard normal distribution.

The cash operating expenses of the regional phone companies during the first half of 1994 were distributed about a mean of$29.02per access line per month, with a standard deviation of$2.85. Company N's operating expenses were$37.21per access line per month in the first half of 1994. Estimate the percentage of regional phone companies whose operating expenses were higher than those of Company N. (Round your answer to two decimal places.)

________%