Finding the Fourth Proportional to 1,359.79, 1,876.39 and 770.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,359.79 : 1,876.39 = 770.20 : x
2. Step 2: Convert to fraction form
   1,359.79/1,876.39 = 770.20/x
3. Step 3: Cross multiply
   1,359.79x = 1,876.39 × 770.20
4. Step 4: Simplify right side
   1,359.79x = 1,445,188.96
5. Step 5: Solve for x
   x = 1,445,188.96/1,359.79
6. Step 6: Final answer
   x = 1,062.81