19/4
To turn a mixed number into an improper fraction, multiply the whole number (4) with the denominator (4) of the proper fraction. Add the numerator (3) of the proper fraction to this product to obtain the numerator of the improper fraction.
4 (whole) × 4 (denominator) = 16
16 + 3 (numerator) = 19
4 3/4 = 19/4 in improper fraction