Finding the Fourth Proportional to 90,358.58, 135,538.96 and 42,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   90,358.58 : 135,538.96 = 42,978.72 : x
2. Step 2: Convert to fraction form
   90,358.58/135,538.96 = 42,978.72/x
3. Step 3: Cross multiply
   90,358.58x = 135,538.96 × 42,978.72
4. Step 4: Simplify right side
   90,358.58x = 5,825,291,010.93
5. Step 5: Solve for x
   x = 5,825,291,010.93/90,358.58
6. Step 6: Final answer
   x = 64,468.60