Finding the Third Proportional to 15,890.25 and 21,085.50

Step by Step Solution

1. Step 1: Write the proportion equation
   15,890.25 : 21,085.50 = 21,085.50 : x
2. Step 2: Convert to fraction form
   15,890.25/21,085.50 = 21,085.50/x
3. Step 3: Cross multiply
   15,890.25x = 21,085.50 × 21,085.50
4. Step 4: Simplify right side
   15,890.25x = 444,598,310.25
5. Step 5: Solve for x
   x = 444,598,310.25/15,890.25
6. Step 6: Final answer
   x = 27,979.32