Finding the Fourth Proportional to 90,978.32, 136,564.52 and 80,514.88

Step by Step Solution

1. Step 1: Write the proportion equation
   90,978.32 : 136,564.52 = 80,514.88 : x
2. Step 2: Convert to fraction form
   90,978.32/136,564.52 = 80,514.88/x
3. Step 3: Cross multiply
   90,978.32x = 136,564.52 × 80,514.88
4. Step 4: Simplify right side
   90,978.32x = 10,995,475,196.07
5. Step 5: Solve for x
   x = 10,995,475,196.07/90,978.32
6. Step 6: Final answer
   x = 120,858.19