Chapter 4 - Probability and Counting Rules - 4-3 The Multiplication Rules and Conditional Probability - Exercises 4-3 - Page 226: 50

a. $0.011$ b. $0.022$ c. $0.978$

a. All had an A average in high school $p=0.47^6=0.011$ b. None had an A average in high school $p=(1-0.47)^6=0.022$ c. At least 1 had an A average in high school This is the complement of (b): $1-0.022=0.978$