Finding the Fourth Proportional to 1,311.42, 1,966.82 and 580.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.42 : 1,966.82 = 580.59 : x
2. Step 2: Convert to fraction form
   1,311.42/1,966.82 = 580.59/x
3. Step 3: Cross multiply
   1,311.42x = 1,966.82 × 580.59
4. Step 4: Simplify right side
   1,311.42x = 1,141,913.12
5. Step 5: Solve for x
   x = 1,141,913.12/1,311.42
6. Step 6: Final answer
   x = 870.75