Discrete random variable

A discret random variable X has the following probability distribution: X :1234567 P(X):c2c2c3cc^22c^27c^2+c Find the value of cdot Also, find the mean of the distribution.

A discret random variable X has the following probability distribution: 1,1,2,3,4,5,6,7P(X):,c,2c,2c,3c,c^(2),2c^(2),7c^(2)+ Find the value of c. Also,find the mean of the distribution.

A random variable is said to be discrete, if