Finding the Third Proportional to 2,309.63 and 3,121.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,309.63 : 3,121.31 = 3,121.31 : x
2. Step 2: Convert to fraction form
   2,309.63/3,121.31 = 3,121.31/x
3. Step 3: Cross multiply
   2,309.63x = 3,121.31 × 3,121.31
4. Step 4: Simplify right side
   2,309.63x = 9,742,591.72
5. Step 5: Solve for x
   x = 9,742,591.72/2,309.63
6. Step 6: Final answer
   x = 4,218.26