Finding the Third Proportional to 642.50 and 1,404.75

Step by Step Solution

1. Step 1: Write the proportion equation
   642.50 : 1,404.75 = 1,404.75 : x
2. Step 2: Convert to fraction form
   642.50/1,404.75 = 1,404.75/x
3. Step 3: Cross multiply
   642.50x = 1,404.75 × 1,404.75
4. Step 4: Simplify right side
   642.50x = 1,973,322.56
5. Step 5: Solve for x
   x = 1,973,322.56/642.50
6. Step 6: Final answer
   x = 3,071.32