Finding the Fourth Proportional to 1,361.15, 1,878.35 and 771.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.15 : 1,878.35 = 771.69 : x
2. Step 2: Convert to fraction form
   1,361.15/1,878.35 = 771.69/x
3. Step 3: Cross multiply
   1,361.15x = 1,878.35 × 771.69
4. Step 4: Simplify right side
   1,361.15x = 1,449,496.45
5. Step 5: Solve for x
   x = 1,449,496.45/1,361.15
6. Step 6: Final answer
   x = 1,064.90