Find the decimal numbers represented in the Binary Coded $($BCD$)$ packed decimal codes. Standard sign values are applied to represented negative numbers by including a $4-$bit sign digit at the left end of a string of packed decimal digits.

$-$ For each of the following packed decimal numbers, show the corresponding decimal value. No space in between.

$-$ If the BCD code is not valid, write 'error'.

$-$ If negative, write the signed value.

$1.0001001100001001$

$1.$

$2.100001010010$

$2.$

$3.010010100110$

$3.$

$4.1101011101000010$

$4.$