Finding the Third Proportional to 4,985.72 and 7,123.78

Step by Step Solution

1. Step 1: Write the proportion equation
   4,985.72 : 7,123.78 = 7,123.78 : x
2. Step 2: Convert to fraction form
   4,985.72/7,123.78 = 7,123.78/x
3. Step 3: Cross multiply
   4,985.72x = 7,123.78 × 7,123.78
4. Step 4: Simplify right side
   4,985.72x = 50,748,259.30
5. Step 5: Solve for x
   x = 50,748,259.30/4,985.72
6. Step 6: Final answer
   x = 10,178.72