Question 1e58dd10

Advanced Math - Nonlinear functions

$x$	$y$
$1$	$11$
$2$	$19$
$3$	$a$

The table shows three values of $x$ and their corresponding values of $y$ for the equation $y = 4 {(2)}^{x} + 3$ . In the table, $a$ is a constant. What is the value of $a$ ?