Finding the Fourth Proportional to 538,870.05, 743,690.43 and 309,457.40

Step by Step Solution

1. Step 1: Write the proportion equation
   538,870.05 : 743,690.43 = 309,457.40 : x
2. Step 2: Convert to fraction form
   538,870.05/743,690.43 = 309,457.40/x
3. Step 3: Cross multiply
   538,870.05x = 743,690.43 × 309,457.40
4. Step 4: Simplify right side
   538,870.05x = 230,140,503,154.23
5. Step 5: Solve for x
   x = 230,140,503,154.23/538,870.05
6. Step 6: Final answer
   x = 427,079.78