Finding the Third Proportional to 18,780 and 39,670.50

Step by Step Solution

1. Step 1: Write the proportion equation
   18,780 : 39,670.50 = 39,670.50 : x
2. Step 2: Convert to fraction form
   18,780/39,670.50 = 39,670.50/x
3. Step 3: Cross multiply
   18,780x = 39,670.50 × 39,670.50
4. Step 4: Simplify right side
   18,780x = 1,573,748,570.25
5. Step 5: Solve for x
   x = 1,573,748,570.25/18,780
6. Step 6: Final answer
   x = 83,799.18