Finding the Fourth Proportional to 1,421.52, 2,128.59 and 1,217.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.52 : 2,128.59 = 1,217.40 : x
2. Step 2: Convert to fraction form
   1,421.52/2,128.59 = 1,217.40/x
3. Step 3: Cross multiply
   1,421.52x = 2,128.59 × 1,217.40
4. Step 4: Simplify right side
   1,421.52x = 2,591,345.47
5. Step 5: Solve for x
   x = 2,591,345.47/1,421.52
6. Step 6: Final answer
   x = 1,822.94