Consider the following frequency table. x 19 20 21 22 23 F(x) 9 1 5 8 2 Let x be the ages of students in a class, and F(x) the corresponding frequency. Determine the following probabilities: (a) P(x≥22 or x<20)= 0.76 (b) P(x≥20)= 0.64 (c) P(19≤x<21)=