Finding the Third Proportional to 21,090 and 42,786

Step by Step Solution

1. Step 1: Write the proportion equation
   21,090 : 42,786 = 42,786 : x
2. Step 2: Convert to fraction form
   21,090/42,786 = 42,786/x
3. Step 3: Cross multiply
   21,090x = 42,786 × 42,786
4. Step 4: Simplify right side
   21,090x = 1,830,641,796
5. Step 5: Solve for x
   x = 1,830,641,796/21,090
6. Step 6: Final answer
   x = 86,801.41