Since $-13.5$ is negative number so $s = 1$

Exponent = $7$ bits, therefore bias = 64

$13.5$ in binary = $1101.1$ = $1.1011 * 2^3$

E = e + bias = $3 + 64$ = $67$ = $1000011$

We store number like

S (1bit) |
E (7 bits) |
M (8bits |

$(1100001110110000)_{2}$ = $(C3B0)_{H}$