Finding the Fourth Proportional to 99,692.88, 137,573.40 and 54,978

Step by Step Solution

1. Step 1: Write the proportion equation
   99,692.88 : 137,573.40 = 54,978 : x
2. Step 2: Convert to fraction form
   99,692.88/137,573.40 = 54,978/x
3. Step 3: Cross multiply
   99,692.88x = 137,573.40 × 54,978
4. Step 4: Simplify right side
   99,692.88x = 7,563,510,385.20
5. Step 5: Solve for x
   x = 7,563,510,385.20/99,692.88
6. Step 6: Final answer
   x = 75,868.11