A researcher determined that the heights of male students in a particular town are normally distributed with a mean of 65 inches and a standard deviation of 1.7. Use the graph above to answer the following questions:
a. What percentage of these students is taller than 66.7 inches?
b. If the data are based on 300 students, how many students are between 61.6 and 68.4 inches tall? Explain.
A median is 65 inches and a standard deviation is 1.7: a. 65 + 1 SD = 65 + 1.7 = 66.7 in It means that there are : 100% - ( 50% + 34% ) = 100% - 84% = 16% students taller than 66.7 inches. b. Heights between 61.6 in and 68.7 in are within 2 standard deviations: 13.5% + 34% + 13.5% + 34% = 95% 0.95 * 300 = 285 There are 285 students between 61.6 in and 68.7 in tall.
