Finding the Fourth Proportional to 505,019.40, 696,925.98 and 278,664.72

Step by Step Solution

1. Step 1: Write the proportion equation
   505,019.40 : 696,925.98 = 278,664.72 : x
2. Step 2: Convert to fraction form
   505,019.40/696,925.98 = 278,664.72/x
3. Step 3: Cross multiply
   505,019.40x = 696,925.98 × 278,664.72
4. Step 4: Simplify right side
   505,019.40x = 194,208,683,077.43
5. Step 5: Solve for x
   x = 194,208,683,077.43/505,019.40
6. Step 6: Final answer
   x = 384,556.88