In a large population of adults, the mean IQ is 110 with a standard deviation of 19. Suppose 45 adults are randomly selected for a market research campaign. (Round to 2 decimal places for all z-values and round all other answers to 4 decimal places, if needed.) (a) The distribution of IQ is approximately normal + (b) The distribution of the sample mean IQ is approximately normal (c) The probability that the sample mean IQ is less than 109 is with a mean of and a standard deviation of

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1471 and the standard deviation was 318. The test scores of four students selected at random are 1910, 1210, 2210, and 1370. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1910 is (Round to two decimal places as needed.)

A person's blood glucose level and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution that is approximately normal with mean ? = 82 and standard deviation ? = 22. Note: After 50 years of age, both the mean and standard deviation tend to increase. For an adult (under 50) after a 12-hour fast, find the following probabilities. (Round your answers to four decimal places.) (a) x is more than 60(b) x is less than 110(c) x is between 60 and 110(d) x is greater than 125 (borderline diabetes starts at 125)

A person's blood glucose level and diabetes are closely related. Let x be a random variable measured in milligrams of glucose per deciliter (1/10 of a liter) of blood. Suppose that after a 12-hour fast, the random variable x will have a distribution that is approximately normal with mean ? = 81 and standard deviation ? = 26. Note: After 50 years of age, both the mean and standard deviation tend to increase. For an adult (under 50) after a 12-hour fast, find the following probabilities. (Round your answers to four decimal places.)   (a) x is more than 60(b) x is less than 110(c) x is between 60 and 110(d) x is greater than 125 (borderline diabetes starts at 125)