Finding the Fourth Proportional to 7,123.47, 9,830.12 and 3,936.70

Step by Step Solution

1. Step 1: Write the proportion equation
   7,123.47 : 9,830.12 = 3,936.70 : x
2. Step 2: Convert to fraction form
   7,123.47/9,830.12 = 3,936.70/x
3. Step 3: Cross multiply
   7,123.47x = 9,830.12 × 3,936.70
4. Step 4: Simplify right side
   7,123.47x = 38,698,233.40
5. Step 5: Solve for x
   x = 38,698,233.40/7,123.47
6. Step 6: Final answer
   x = 5,432.50