Finding the Fourth Proportional to 42,702.51, 64,042.72 and 12,709.71

Step by Step Solution

1. Step 1: Write the proportion equation
   42,702.51 : 64,042.72 = 12,709.71 : x
2. Step 2: Convert to fraction form
   42,702.51/64,042.72 = 12,709.71/x
3. Step 3: Cross multiply
   42,702.51x = 64,042.72 × 12,709.71
4. Step 4: Simplify right side
   42,702.51x = 813,964,367.04
5. Step 5: Solve for x
   x = 813,964,367.04/42,702.51
6. Step 6: Final answer
   x = 19,061.28