Considering the resistor network below, calculate all answers to 2 decimal places.

a) What is the combined circuit resistance (R_T) in ohms?
b) Calculate the current through resistor R4 (i_R4) in mA.
c) What is the voltage drop (V_drop) across resistor R4?
d) Provide the value of resistor R4 in ohms.

Resistor Network:

R_T = ?
i_R4 = ?
V_drop = ?
R4 = ?

Note: Please remove unnecessary spaces and words from the question.