Finding the Fourth Proportional to 1,511.46, 2,085.30 and 921.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,511.46 : 2,085.30 = 921.78 : x
2. Step 2: Convert to fraction form
   1,511.46/2,085.30 = 921.78/x
3. Step 3: Cross multiply
   1,511.46x = 2,085.30 × 921.78
4. Step 4: Simplify right side
   1,511.46x = 1,922,187.83
5. Step 5: Solve for x
   x = 1,922,187.83/1,511.46
6. Step 6: Final answer
   x = 1,271.74