Solution: (75%+68%+85%+80%)-300%=8%
Explanation: Because when 75% of 100 people have a washing machine and 68% have a computer, the minimum probability of at least two people is 75%+68%- 100%, while at least three people have a washing machine and 68% have a washing machine.
-Quote the answer of "Nangong Qilao".