To find the expected value of \( y \) when \( x = 72 \) using the given equation of the line of best fit \( y = x - 49 \), we can substitute \( x = 72 \) into the equation.
\[ y = 72 - 49 \] \[ y = 23 \]
So, the expected value of \( y \) when \( x = 72 \) is \( 23 \).