For each person the probability of he/she having a bloodtype O negative is 7% then the probability of one person having a different blood type is 93%. We want all of them to have a different bloodtype, therefore we need to calculate the product of each to have a different bloodtype.
![p=((93)/(100))^4=0.93^4=0.748](https://img.qammunity.org/2023/formulas/mathematics/college/ukf9wnuv4r658z7q7t08x7vvnn0o17e0we.png)
The probability is 0.748 or 74.8%.