Finding the Fourth Proportional to 1,379.31, 2,069.61 and 558.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.31 : 2,069.61 = 558.18 : x
2. Step 2: Convert to fraction form
   1,379.31/2,069.61 = 558.18/x
3. Step 3: Cross multiply
   1,379.31x = 2,069.61 × 558.18
4. Step 4: Simplify right side
   1,379.31x = 1,155,214.91
5. Step 5: Solve for x
   x = 1,155,214.91/1,379.31
6. Step 6: Final answer
   x = 837.53