Finding the Third Proportional to 4,123.31 and 8,390.63

Step by Step Solution

1. Step 1: Write the proportion equation
   4,123.31 : 8,390.63 = 8,390.63 : x
2. Step 2: Convert to fraction form
   4,123.31/8,390.63 = 8,390.63/x
3. Step 3: Cross multiply
   4,123.31x = 8,390.63 × 8,390.63
4. Step 4: Simplify right side
   4,123.31x = 70,402,587.89
5. Step 5: Solve for x
   x = 70,402,587.89/4,123.31
6. Step 6: Final answer
   x = 17,074.28