Finding the Fourth Proportional to 31,028.64, 42,827.40 and 19,870.08

Step by Step Solution

1. Step 1: Write the proportion equation
   31,028.64 : 42,827.40 = 19,870.08 : x
2. Step 2: Convert to fraction form
   31,028.64/42,827.40 = 19,870.08/x
3. Step 3: Cross multiply
   31,028.64x = 42,827.40 × 19,870.08
4. Step 4: Simplify right side
   31,028.64x = 850,983,864.19
5. Step 5: Solve for x
   x = 850,983,864.19/31,028.64
6. Step 6: Final answer
   x = 27,425.75