Finding the Fourth Proportional to 1,429.68, 1,972.95 and 840.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,429.68 : 1,972.95 = 840.09 : x
2. Step 2: Convert to fraction form
   1,429.68/1,972.95 = 840.09/x
3. Step 3: Cross multiply
   1,429.68x = 1,972.95 × 840.09
4. Step 4: Simplify right side
   1,429.68x = 1,657,455.57
5. Step 5: Solve for x
   x = 1,657,455.57/1,429.68
6. Step 6: Final answer
   x = 1,159.32