Finding the Fourth Proportional to 1,407.48, 1,942.42 and 818.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.48 : 1,942.42 = 818.20 : x
2. Step 2: Convert to fraction form
   1,407.48/1,942.42 = 818.20/x
3. Step 3: Cross multiply
   1,407.48x = 1,942.42 × 818.20
4. Step 4: Simplify right side
   1,407.48x = 1,589,288.04
5. Step 5: Solve for x
   x = 1,589,288.04/1,407.48
6. Step 6: Final answer
   x = 1,129.17