Finding the Fourth Proportional to 1,424.87, 2,136.55 and 839.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,424.87 : 2,136.55 = 839.98 : x
2. Step 2: Convert to fraction form
   1,424.87/2,136.55 = 839.98/x
3. Step 3: Cross multiply
   1,424.87x = 2,136.55 × 839.98
4. Step 4: Simplify right side
   1,424.87x = 1,794,659.27
5. Step 5: Solve for x
   x = 1,794,659.27/1,424.87
6. Step 6: Final answer
   x = 1,259.52