Finding the Fourth Proportional to 42,936.28, 64,405.86 and 12,951.88

Step by Step Solution

1. Step 1: Write the proportion equation
   42,936.28 : 64,405.86 = 12,951.88 : x
2. Step 2: Convert to fraction form
   42,936.28/64,405.86 = 12,951.88/x
3. Step 3: Cross multiply
   42,936.28x = 64,405.86 × 12,951.88
4. Step 4: Simplify right side
   42,936.28x = 834,176,970.02
5. Step 5: Solve for x
   x = 834,176,970.02/42,936.28
6. Step 6: Final answer
   x = 19,428.25