Finding the Fourth Proportional to 1,355.56, 1,866.18 and 1,212.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,355.56 : 1,866.18 = 1,212.52 : x
2. Step 2: Convert to fraction form
   1,355.56/1,866.18 = 1,212.52/x
3. Step 3: Cross multiply
   1,355.56x = 1,866.18 × 1,212.52
4. Step 4: Simplify right side
   1,355.56x = 2,262,780.57
5. Step 5: Solve for x
   x = 2,262,780.57/1,355.56
6. Step 6: Final answer
   x = 1,669.26