Finding the Fourth Proportional to 1,407.10, 1,941.81 and 817.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.10 : 1,941.81 = 817.78 : x
2. Step 2: Convert to fraction form
   1,407.10/1,941.81 = 817.78/x
3. Step 3: Cross multiply
   1,407.10x = 1,941.81 × 817.78
4. Step 4: Simplify right side
   1,407.10x = 1,587,973.38
5. Step 5: Solve for x
   x = 1,587,973.38/1,407.10
6. Step 6: Final answer
   x = 1,128.54