Finding the Third Proportional to 42,720 and 64,597.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,720 : 64,597.50 = 64,597.50 : x
2. Step 2: Convert to fraction form
   42,720/64,597.50 = 64,597.50/x
3. Step 3: Cross multiply
   42,720x = 64,597.50 × 64,597.50
4. Step 4: Simplify right side
   42,720x = 4,172,837,006.25
5. Step 5: Solve for x
   x = 4,172,837,006.25/42,720
6. Step 6: Final answer
   x = 97,678.77