Finding the Fourth Proportional to 1,300.79, 1,949.87 and 520.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,300.79 : 1,949.87 = 520.43 : x
2. Step 2: Convert to fraction form
   1,300.79/1,949.87 = 520.43/x
3. Step 3: Cross multiply
   1,300.79x = 1,949.87 × 520.43
4. Step 4: Simplify right side
   1,300.79x = 1,014,762.40
5. Step 5: Solve for x
   x = 1,014,762.40/1,300.79
6. Step 6: Final answer
   x = 780.11