Finding the Fourth Proportional to 1,087.30, 1,628.55 and 841.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.30 : 1,628.55 = 841.90 : x
2. Step 2: Convert to fraction form
   1,087.30/1,628.55 = 841.90/x
3. Step 3: Cross multiply
   1,087.30x = 1,628.55 × 841.90
4. Step 4: Simplify right side
   1,087.30x = 1,371,076.25
5. Step 5: Solve for x
   x = 1,371,076.25/1,087.30
6. Step 6: Final answer
   x = 1,260.99