Probability. Qn 25.

I’m working on a Mathematics question and need guidance to help me study.

The number of adults living in homes on a randomly selected city block is described by the following probability distribution.

Number of adults, x | 1 | 2 | 3 | 4 or more |
---|---|---|---|---|

Probability, P(x) | 0.25 | 0.50 | 0.15 | ??? |

What is the probability that 4 or more adults reside at a randomly selected home?