Finding the Third Proportional to 21,206 and 42,409.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,206 : 42,409.50 = 42,409.50 : x
2. Step 2: Convert to fraction form
   21,206/42,409.50 = 42,409.50/x
3. Step 3: Cross multiply
   21,206x = 42,409.50 × 42,409.50
4. Step 4: Simplify right side
   21,206x = 1,798,565,690.25
5. Step 5: Solve for x
   x = 1,798,565,690.25/21,206
6. Step 6: Final answer
   x = 84,814.00