Finding the Fourth Proportional to 1,361.61, 1,878.75 and 830.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,361.61 : 1,878.75 = 830.34 : x
2. Step 2: Convert to fraction form
   1,361.61/1,878.75 = 830.34/x
3. Step 3: Cross multiply
   1,361.61x = 1,878.75 × 830.34
4. Step 4: Simplify right side
   1,361.61x = 1,560,001.28
5. Step 5: Solve for x
   x = 1,560,001.28/1,361.61
6. Step 6: Final answer
   x = 1,145.70