Finding the Fourth Proportional to 39,172.72, 58,737 and 12,870.40

Step by Step Solution

1. Step 1: Write the proportion equation
   39,172.72 : 58,737 = 12,870.40 : x
2. Step 2: Convert to fraction form
   39,172.72/58,737 = 12,870.40/x
3. Step 3: Cross multiply
   39,172.72x = 58,737 × 12,870.40
4. Step 4: Simplify right side
   39,172.72x = 755,968,684.80
5. Step 5: Solve for x
   x = 755,968,684.80/39,172.72
6. Step 6: Final answer
   x = 19,298.35