Finding the Fourth Proportional to 1,284.89, 1,925.69 and 1,111.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,284.89 : 1,925.69 = 1,111.55 : x
2. Step 2: Convert to fraction form
   1,284.89/1,925.69 = 1,111.55/x
3. Step 3: Cross multiply
   1,284.89x = 1,925.69 × 1,111.55
4. Step 4: Simplify right side
   1,284.89x = 2,140,485.53
5. Step 5: Solve for x
   x = 2,140,485.53/1,284.89
6. Step 6: Final answer
   x = 1,665.90