Finding the Fourth Proportional to 1,379.72, 2,069.55 and 557.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.72 : 2,069.55 = 557.98 : x
2. Step 2: Convert to fraction form
   1,379.72/2,069.55 = 557.98/x
3. Step 3: Cross multiply
   1,379.72x = 2,069.55 × 557.98
4. Step 4: Simplify right side
   1,379.72x = 1,154,762.34
5. Step 5: Solve for x
   x = 1,154,762.34/1,379.72
6. Step 6: Final answer
   x = 836.95