Finding the Fourth Proportional to 57,139.88, 78,861.30 and 31,991

Step by Step Solution

1. Step 1: Write the proportion equation
   57,139.88 : 78,861.30 = 31,991 : x
2. Step 2: Convert to fraction form
   57,139.88/78,861.30 = 31,991/x
3. Step 3: Cross multiply
   57,139.88x = 78,861.30 × 31,991
4. Step 4: Simplify right side
   57,139.88x = 2,522,851,848.30
5. Step 5: Solve for x
   x = 2,522,851,848.30/57,139.88
6. Step 6: Final answer
   x = 44,152.21