Finding the Fourth Proportional to 116,978.32, 161,431.65 and 65,990.89

Step by Step Solution

1. Step 1: Write the proportion equation
   116,978.32 : 161,431.65 = 65,990.89 : x
2. Step 2: Convert to fraction form
   116,978.32/161,431.65 = 65,990.89/x
3. Step 3: Cross multiply
   116,978.32x = 161,431.65 × 65,990.89
4. Step 4: Simplify right side
   116,978.32x = 10,653,018,092.69
5. Step 5: Solve for x
   x = 10,653,018,092.69/116,978.32
6. Step 6: Final answer
   x = 91,068.31