Finding the Fourth Proportional to 91,902.78, 137,231.64 and 72,970.38

Step by Step Solution

1. Step 1: Write the proportion equation
   91,902.78 : 137,231.64 = 72,970.38 : x
2. Step 2: Convert to fraction form
   91,902.78/137,231.64 = 72,970.38/x
3. Step 3: Cross multiply
   91,902.78x = 137,231.64 × 72,970.38
4. Step 4: Simplify right side
   91,902.78x = 10,013,844,918.82
5. Step 5: Solve for x
   x = 10,013,844,918.82/91,902.78
6. Step 6: Final answer
   x = 108,961.28