Finding the Third Proportional to 18,978.50 and 28,380

Step by Step Solution

1. Step 1: Write the proportion equation
   18,978.50 : 28,380 = 28,380 : x
2. Step 2: Convert to fraction form
   18,978.50/28,380 = 28,380/x
3. Step 3: Cross multiply
   18,978.50x = 28,380 × 28,380
4. Step 4: Simplify right side
   18,978.50x = 805,424,400
5. Step 5: Solve for x
   x = 805,424,400/18,978.50
6. Step 6: Final answer
   x = 42,438.78