Finding the Fourth Proportional to 1,249.61, 1,869.77 and 785.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,249.61 : 1,869.77 = 785.21 : x
2. Step 2: Convert to fraction form
   1,249.61/1,869.77 = 785.21/x
3. Step 3: Cross multiply
   1,249.61x = 1,869.77 × 785.21
4. Step 4: Simplify right side
   1,249.61x = 1,468,148.83
5. Step 5: Solve for x
   x = 1,468,148.83/1,249.61
6. Step 6: Final answer
   x = 1,174.89