Finding the Fourth Proportional to 3,111.86, 4,666.18 and 920.30

Step by Step Solution

1. Step 1: Write the proportion equation
   3,111.86 : 4,666.18 = 920.30 : x
2. Step 2: Convert to fraction form
   3,111.86/4,666.18 = 920.30/x
3. Step 3: Cross multiply
   3,111.86x = 4,666.18 × 920.30
4. Step 4: Simplify right side
   3,111.86x = 4,294,280.85
5. Step 5: Solve for x
   x = 4,294,280.85/3,111.86
6. Step 6: Final answer
   x = 1,379.97