Finding the Fourth Proportional to 1,361.31, 1,878.59 and 771.84

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.31 : 1,878.59 = 771.84 : x
2. Step 2: Convert to fraction form
   1,361.31/1,878.59 = 771.84/x
3. Step 3: Cross multiply
   1,361.31x = 1,878.59 × 771.84
4. Step 4: Simplify right side
   1,361.31x = 1,449,967.05
5. Step 5: Solve for x
   x = 1,449,967.05/1,361.31
6. Step 6: Final answer
   x = 1,065.13