Finding the Fourth Proportional to 72,109.71, 99,369.63 and 55,133.15

Step by Step Solution

1. Step 1: Write the proportion equation
   72,109.71 : 99,369.63 = 55,133.15 : x
2. Step 2: Convert to fraction form
   72,109.71/99,369.63 = 55,133.15/x
3. Step 3: Cross multiply
   72,109.71x = 99,369.63 × 55,133.15
4. Step 4: Simplify right side
   72,109.71x = 5,478,560,219.39
5. Step 5: Solve for x
   x = 5,478,560,219.39/72,109.71
6. Step 6: Final answer
   x = 75,975.35