Finding the Third Proportional to 9,912 and 21,457.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,912 : 21,457.50 = 21,457.50 : x
2. Step 2: Convert to fraction form
   9,912/21,457.50 = 21,457.50/x
3. Step 3: Cross multiply
   9,912x = 21,457.50 × 21,457.50
4. Step 4: Simplify right side
   9,912x = 460,424,306.25
5. Step 5: Solve for x
   x = 460,424,306.25/9,912
6. Step 6: Final answer
   x = 46,451.20