Finding the Fourth Proportional to 1,429.55, 1,972.55 and 840.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.55 : 1,972.55 = 840.20 : x
2. Step 2: Convert to fraction form
   1,429.55/1,972.55 = 840.20/x
3. Step 3: Cross multiply
   1,429.55x = 1,972.55 × 840.20
4. Step 4: Simplify right side
   1,429.55x = 1,657,337.24
5. Step 5: Solve for x
   x = 1,657,337.24/1,429.55
6. Step 6: Final answer
   x = 1,159.34