Employees were asked how many times per week they exercised. The frequency table shows the results of the survey.
Number of times exercised per week: 0 1 2 3 4 5 6 7 8
Frequency: 5 10 2 9 33 12 15 3 1
Find: (b) P(x < 4) (c) P(x = 6) (d) P(x (greater than or equal to sign) 5)