Finding the Fourth Proportional to 1,429.78, 1,972.65 and 840.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.78 : 1,972.65 = 840.34 : x
2. Step 2: Convert to fraction form
   1,429.78/1,972.65 = 840.34/x
3. Step 3: Cross multiply
   1,429.78x = 1,972.65 × 840.34
4. Step 4: Simplify right side
   1,429.78x = 1,657,696.70
5. Step 5: Solve for x
   x = 1,657,696.70/1,429.78
6. Step 6: Final answer
   x = 1,159.41