Instruction 5 $$\begin{array} { | c | c | c | c | c | } \hline X & 0 & 1 & 2 & 3 \\\hline p ( X ) & 0.35 & 0.35 & 0.25 & 0.05 \\\hline\end{array}$$

Instruction 5.1
The following table contains the probability distribution for X = the number of retransmissions necessary to successfully transmit a 1024K data package through a double satellite media.
$$\begin{array} { | c | c | c | c | c | } \hline X & 0 & 1 & 2 & 3 \\\hline p ( X ) & 0.35 & 0.35 & 0.25 & 0.05 \\\hline\end{array}$$
-Referring to Instruction 5.1,the mean or expected value for the number of retransmissions is ______.