please help

I am taking a survey and trying to find out information about the students I teach, I ask the following two questions: 1. How many classes are you taking this summer? 2. How long do you expect to take on your first exam? After looking at data on question 2, I determine that there is a 60% chance that a student will finish the exam in less than an hour. Assuming this value is true, and I take a random sample of 20 students, what is the probability that at least 9 but no more than 12 of the students finish the exam in less than an hour? APPENDIX B Tables 877 TABLE II (continued) 20 .70 199 860 206 1035 005 1990 829 549 167 1035 105 1.000 -964 398 -127 127 905 1944 1000 TODO ISUbWHE 648 .297 091 1.OOD ,999 .515 217 1 ,010 .059 109 koon 930 .WOD .721 .403 1.000 .151 034 1.000 004 1.000 982 610 1.OOO 304 1095 1.000 1015 001 .996 .950 LODO 1,000 787 5030 213 904 .985 1.000 905 1,000 390 1.0100 .131 DOO 10 966 849 1:000 547 1278 1.010 000 1/000 .941 1 1000 783 1.010 1485 1.000 164 013 12 1:000 909 1.on 352 1.00Q 13 1.0ON 1.010 1.000 973 873 1.000 .602 LOOP .184 036 1.010 905 451