Finding the Fourth Proportional to 1,555.51, 2,147.61 and 996.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,555.51 : 2,147.61 = 996.21 : x
2. Step 2: Convert to fraction form
   1,555.51/2,147.61 = 996.21/x
3. Step 3: Cross multiply
   1,555.51x = 2,147.61 × 996.21
4. Step 4: Simplify right side
   1,555.51x = 2,139,470.56
5. Step 5: Solve for x
   x = 2,139,470.56/1,555.51
6. Step 6: Final answer
   x = 1,375.41