Finding the Fourth Proportional to 314,819.74, 472,090.28 and 90,128.98

Step by Step Solution

1. Step 1: Write the proportion equation
   314,819.74 : 472,090.28 = 90,128.98 : x
2. Step 2: Convert to fraction form
   314,819.74/472,090.28 = 90,128.98/x
3. Step 3: Cross multiply
   314,819.74x = 472,090.28 × 90,128.98
4. Step 4: Simplify right side
   314,819.74x = 42,549,015,404.31
5. Step 5: Solve for x
   x = 42,549,015,404.31/314,819.74
6. Step 6: Final answer
   x = 135,153.58