Finding the Fourth Proportional to 1,359.89, 1,876.77 and 770.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,359.89 : 1,876.77 = 770.61 : x
2. Step 2: Convert to fraction form
   1,359.89/1,876.77 = 770.61/x
3. Step 3: Cross multiply
   1,359.89x = 1,876.77 × 770.61
4. Step 4: Simplify right side
   1,359.89x = 1,446,264.77
5. Step 5: Solve for x
   x = 1,446,264.77/1,359.89
6. Step 6: Final answer
   x = 1,063.52