Finding the Fourth Proportional to 1,913.72, 2,640.73 and 1,284.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,913.72 : 2,640.73 = 1,284.12 : x
2. Step 2: Convert to fraction form
   1,913.72/2,640.73 = 1,284.12/x
3. Step 3: Cross multiply
   1,913.72x = 2,640.73 × 1,284.12
4. Step 4: Simplify right side
   1,913.72x = 3,391,007.61
5. Step 5: Solve for x
   x = 3,391,007.61/1,913.72
6. Step 6: Final answer
   x = 1,771.95