Finding the Third Proportional to 9,915 and 14,521.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,915 : 14,521.50 = 14,521.50 : x
2. Step 2: Convert to fraction form
   9,915/14,521.50 = 14,521.50/x
3. Step 3: Cross multiply
   9,915x = 14,521.50 × 14,521.50
4. Step 4: Simplify right side
   9,915x = 210,873,962.25
5. Step 5: Solve for x
   x = 210,873,962.25/9,915
6. Step 6: Final answer
   x = 21,268.18