Finding the Fourth Proportional to 1,385.89, 1,912.48 and 826.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.89 : 1,912.48 = 826.35 : x
2. Step 2: Convert to fraction form
   1,385.89/1,912.48 = 826.35/x
3. Step 3: Cross multiply
   1,385.89x = 1,912.48 × 826.35
4. Step 4: Simplify right side
   1,385.89x = 1,580,368.61
5. Step 5: Solve for x
   x = 1,580,368.61/1,385.89
6. Step 6: Final answer
   x = 1,140.33