Finding the Fourth Proportional to 1,851.69, 2,555.59 and 1,222.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,851.69 : 2,555.59 = 1,222.09 : x
2. Step 2: Convert to fraction form
   1,851.69/2,555.59 = 1,222.09/x
3. Step 3: Cross multiply
   1,851.69x = 2,555.59 × 1,222.09
4. Step 4: Simplify right side
   1,851.69x = 3,123,154.87
5. Step 5: Solve for x
   x = 3,123,154.87/1,851.69
6. Step 6: Final answer
   x = 1,686.65