Finding the Fourth Proportional to 213,147.69, 319,603.98 and 86,755.50

Step by Step Solution

1. Step 1: Write the proportion equation
   213,147.69 : 319,603.98 = 86,755.50 : x
2. Step 2: Convert to fraction form
   213,147.69/319,603.98 = 86,755.50/x
3. Step 3: Cross multiply
   213,147.69x = 319,603.98 × 86,755.50
4. Step 4: Simplify right side
   213,147.69x = 27,727,403,086.89
5. Step 5: Solve for x
   x = 27,727,403,086.89/213,147.69
6. Step 6: Final answer
   x = 130,085.40