Question 1104390
All those probabilities add up to 1.000, of course.

ONE WAY:
Adding up the probabilities of 5, 6, or 7+ members in a family, you get
0,079+0.030+0.019=0.127 ,
and that is the probability that the randomly selected family will have 5 our more members, 12.7%.
The rest of the families (100%-12.7%) must have less than 5 members.
The probability of three randomly selected family having less than 5 members is
1.00 - 0.127 = 0.873 (87.3%).


ANOTHER WAY:
You could get the same result by adding
0.464+0.212+0.197 = 0.873.
(I just preferred to add the smaller numbers).