Finding the Fourth Proportional to 99,989.19, 138,019.83 and 57,564.63

Step by Step Solution

1. Step 1: Write the proportion equation
   99,989.19 : 138,019.83 = 57,564.63 : x
2. Step 2: Convert to fraction form
   99,989.19/138,019.83 = 57,564.63/x
3. Step 3: Cross multiply
   99,989.19x = 138,019.83 × 57,564.63
4. Step 4: Simplify right side
   99,989.19x = 7,945,060,446.61
5. Step 5: Solve for x
   x = 7,945,060,446.61/99,989.19
6. Step 6: Final answer
   x = 79,459.19