Finding the Third Proportional to 642.38 and 1,499.63

Step by Step Solution

1. Step 1: Write the proportion equation
   642.38 : 1,499.63 = 1,499.63 : x
2. Step 2: Convert to fraction form
   642.38/1,499.63 = 1,499.63/x
3. Step 3: Cross multiply
   642.38x = 1,499.63 × 1,499.63
4. Step 4: Simplify right side
   642.38x = 2,248,875.14
5. Step 5: Solve for x
   x = 2,248,875.14/642.38
6. Step 6: Final answer
   x = 3,500.88