Finding the Fourth Proportional to 1,215.48, 1,820.61 and 1,129.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.48 : 1,820.61 = 1,129.98 : x
2. Step 2: Convert to fraction form
   1,215.48/1,820.61 = 1,129.98/x
3. Step 3: Cross multiply
   1,215.48x = 1,820.61 × 1,129.98
4. Step 4: Simplify right side
   1,215.48x = 2,057,252.89
5. Step 5: Solve for x
   x = 2,057,252.89/1,215.48
6. Step 6: Final answer
   x = 1,692.54