In a probability model, the sum of all probabilities must equal 1. Given the probabilities for the letters Y, C, A, R, and the value of \( x \) for E, we can set up the following equation to find \( x \):
\[ P(Y) + P(C) + P(A) + P(R) + P(E) + P(S) = 1 \]
Substituting the given probabilities into the equation:
\[ 0.25 + 0.18 + 0.30 + 0.17 + x + P(S) = 1 \]
Now, let's sum the known probabilities:
\[ 0.25 + 0.18 + 0.30 + 0.17 = 0.90 \]
Now we can substitute this into our equation:
\[ 0.90 + x + P(S) = 1 \]
Assuming P(S) is not given (since we haven't any value for it), we will just consider:
\[ 0.90 + x = 1 \]
Solving for \( x \):
\[ x = 1 - 0.90 \] \[ x = 0.10 \]
Therefore, the value of \( x \) is 0.10.