Finding the Fourth Proportional to 71,938.78, 99,275.71 and 39,672.60

Step by Step Solution

1. Step 1: Write the proportion equation
   71,938.78 : 99,275.71 = 39,672.60 : x
2. Step 2: Convert to fraction form
   71,938.78/99,275.71 = 39,672.60/x
3. Step 3: Cross multiply
   71,938.78x = 99,275.71 × 39,672.60
4. Step 4: Simplify right side
   71,938.78x = 3,938,525,532.55
5. Step 5: Solve for x
   x = 3,938,525,532.55/71,938.78
6. Step 6: Final answer
   x = 54,748.29