The following table shows the probability distribution for a discrete random variable.

Answer: C. 30.47
Step-by-step explanation:
The mean of discrete random variable i.e. the expected value of X is given by :-
[tex]E(X)=\sum^{i=n}_{i=1} X_iP(X_i)[/tex]
Now by using the given table, the expected value of X is given by :-
[tex]\\\\\Rightarrow\ E(X)=23\cdot (0.16)+25\cdot(0.09)+26\cdot(0.18)+31\cdot(0.12)+34\cdot(0.24)+38\cdot(0.21)\\\\\Rightarrow\ E(X)=30.47[/tex]
Hence, the mean of discrete random variable= 30.47