i need help my math lab and stats

Here is an example of what the problems are like: there is a 0.1755 probability that a best-of-seven contest will last four games, a 0.1836 probability that it will last five games, a 0.2073 probability that it will last six games, and a 0.4336 probability that it will last seven games. Verify that this is a probability distribution. Find its mean and standard deviation. Is it unusual for a team to “sweep” by winning in four games?

I need to find someone who can help me to complete the question sets which are each 10-20 questions long.