For Exercise 1.70, see page 40; for 1.71 to 1.73, see pages 41-42; for 1.74 to 1.77, see pages 44-45; for 1.78, see page 46; for 1.79 and 1.80, see page 49; for 1.81 and 1.82, see page 50; and for 1.83 and 1.84, see page 53.
1.79 Find the proportion.
Use the fact that the ISTEP scores from Exercise 1.76 (page 44) are approximately Normal, . Find the proportion of students who have scores less than 620. Find the proportion of students who have scores greater than or equal to 620. Sketch the relationship between these two calculations using pictures of Normal curves similar to the ones given in Example 1.34 (page 46).
1.79
0.8264. 0.1736.