Finding the Fourth Proportional to 1,007.60, 1,390.52 and 565.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.60 : 1,390.52 = 565.48 : x
2. Step 2: Convert to fraction form
   1,007.60/1,390.52 = 565.48/x
3. Step 3: Cross multiply
   1,007.60x = 1,390.52 × 565.48
4. Step 4: Simplify right side
   1,007.60x = 786,311.25
5. Step 5: Solve for x
   x = 786,311.25/1,007.60
6. Step 6: Final answer
   x = 780.38