Finding the Fourth Proportional to 1,361.73, 1,878.69 and 830.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.73 : 1,878.69 = 830.40 : x
2. Step 2: Convert to fraction form
   1,361.73/1,878.69 = 830.40/x
3. Step 3: Cross multiply
   1,361.73x = 1,878.69 × 830.40
4. Step 4: Simplify right side
   1,361.73x = 1,560,064.18
5. Step 5: Solve for x
   x = 1,560,064.18/1,361.73
6. Step 6: Final answer
   x = 1,145.65