Finding the Fourth Proportional to 2,167.47, 2,991.15 and 1,223.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,167.47 : 2,991.15 = 1,223.31 : x
2. Step 2: Convert to fraction form
   2,167.47/2,991.15 = 1,223.31/x
3. Step 3: Cross multiply
   2,167.47x = 2,991.15 × 1,223.31
4. Step 4: Simplify right side
   2,167.47x = 3,659,097.59
5. Step 5: Solve for x
   x = 3,659,097.59/2,167.47
6. Step 6: Final answer
   x = 1,688.19