Finding the Fourth Proportional to 141,866.78, 212,656.55 and 91,978.58

Step by Step Solution

1. Step 1: Write the proportion equation
   141,866.78 : 212,656.55 = 91,978.58 : x
2. Step 2: Convert to fraction form
   141,866.78/212,656.55 = 91,978.58/x
3. Step 3: Cross multiply
   141,866.78x = 212,656.55 × 91,978.58
4. Step 4: Simplify right side
   141,866.78x = 19,559,847,496.70
5. Step 5: Solve for x
   x = 19,559,847,496.70/141,866.78
6. Step 6: Final answer
   x = 137,874.75