Finding the Third Proportional to 8,421.50 and 12,749.50

Step by Step Solution

1. Step 1: Write the proportion equation
   8,421.50 : 12,749.50 = 12,749.50 : x
2. Step 2: Convert to fraction form
   8,421.50/12,749.50 = 12,749.50/x
3. Step 3: Cross multiply
   8,421.50x = 12,749.50 × 12,749.50
4. Step 4: Simplify right side
   8,421.50x = 162,549,750.25
5. Step 5: Solve for x
   x = 162,549,750.25/8,421.50
6. Step 6: Final answer
   x = 19,301.76