Evaluate the expression for k = 10.

To evaluate the expression \( 1.9k \) for \( k = 10 \), substitute \( k \) with 10:

\[ 1.9k = 1.9 \times 10 \]

Calculating this gives:

\[ 1.9 \times 10 = 19 \]

Thus, the value of the expression \( 1.9k \) when \( k = 10 \) is \( \boxed{19} \).