Finding the Third Proportional to 4,890 and 10,090.50

Step by Step Solution

1. Step 1: Write the proportion equation
   4,890 : 10,090.50 = 10,090.50 : x
2. Step 2: Convert to fraction form
   4,890/10,090.50 = 10,090.50/x
3. Step 3: Cross multiply
   4,890x = 10,090.50 × 10,090.50
4. Step 4: Simplify right side
   4,890x = 101,818,190.25
5. Step 5: Solve for x
   x = 101,818,190.25/4,890
6. Step 6: Final answer
   x = 20,821.72