Finding the Fourth Proportional to 1,407.86, 1,942.68 and 818.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.86 : 1,942.68 = 818.30 : x
2. Step 2: Convert to fraction form
   1,407.86/1,942.68 = 818.30/x
3. Step 3: Cross multiply
   1,407.86x = 1,942.68 × 818.30
4. Step 4: Simplify right side
   1,407.86x = 1,589,695.04
5. Step 5: Solve for x
   x = 1,589,695.04/1,407.86
6. Step 6: Final answer
   x = 1,129.16