Finding the Fourth Proportional to 1,361.36, 1,878.72 and 830.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.36 : 1,878.72 = 830.60 : x
2. Step 2: Convert to fraction form
   1,361.36/1,878.72 = 830.60/x
3. Step 3: Cross multiply
   1,361.36x = 1,878.72 × 830.60
4. Step 4: Simplify right side
   1,361.36x = 1,560,464.83
5. Step 5: Solve for x
   x = 1,560,464.83/1,361.36
6. Step 6: Final answer
   x = 1,146.25