Although an ideal ammeter has an internal resistance of zero, this theoretical ideal is...

Although an ideal ammeter has an internal resistance of zero, this theoretical ideal is usually not met in practice. The ammeter in Figure P19.77 has an internal resistance of and is used to measure the current in a circuit containing a resistor with as shown. How much does this non ideal ammeter affect the circuit? That is, what is the fractional change in the current when the ammeter is attached?