Finding the Third Proportional to 61,200 and 89,640

Step by Step Solution

1. Step 1: Write the proportion equation
   61,200 : 89,640 = 89,640 : x
2. Step 2: Convert to fraction form
   61,200/89,640 = 89,640/x
3. Step 3: Cross multiply
   61,200x = 89,640 × 89,640
4. Step 4: Simplify right side
   61,200x = 8,035,329,600
5. Step 5: Solve for x
   x = 8,035,329,600/61,200
6. Step 6: Final answer
   x = 131,296.24