Finding the Fourth Proportional to 1,377.64, 1,901.18 and 818.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,377.64 : 1,901.18 = 818.55 : x
2. Step 2: Convert to fraction form
   1,377.64/1,901.18 = 818.55/x
3. Step 3: Cross multiply
   1,377.64x = 1,901.18 × 818.55
4. Step 4: Simplify right side
   1,377.64x = 1,556,210.89
5. Step 5: Solve for x
   x = 1,556,210.89/1,377.64
6. Step 6: Final answer
   x = 1,129.62