Finding the Fourth Proportional to 165,978.78, 248,840.55 and 85,930.93

Step by Step Solution

1. Step 1: Write the proportion equation
   165,978.78 : 248,840.55 = 85,930.93 : x
2. Step 2: Convert to fraction form
   165,978.78/248,840.55 = 85,930.93/x
3. Step 3: Cross multiply
   165,978.78x = 248,840.55 × 85,930.93
4. Step 4: Simplify right side
   165,978.78x = 21,383,099,883.21
5. Step 5: Solve for x
   x = 21,383,099,883.21/165,978.78
6. Step 6: Final answer
   x = 128,830.33