Finding the Fourth Proportional to 1,402.31, 1,935.19 and 812.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,402.31 : 1,935.19 = 812.89 : x
2. Step 2: Convert to fraction form
   1,402.31/1,935.19 = 812.89/x
3. Step 3: Cross multiply
   1,402.31x = 1,935.19 × 812.89
4. Step 4: Simplify right side
   1,402.31x = 1,573,089.15
5. Step 5: Solve for x
   x = 1,573,089.15/1,402.31
6. Step 6: Final answer
   x = 1,121.78