Finding the Fourth Proportional to 13,987.34, 21,057.57 and 12,762.62

Step by Step Solution

1. Step 1: Write the proportion equation
   13,987.34 : 21,057.57 = 12,762.62 : x
2. Step 2: Convert to fraction form
   13,987.34/21,057.57 = 12,762.62/x
3. Step 3: Cross multiply
   13,987.34x = 21,057.57 × 12,762.62
4. Step 4: Simplify right side
   13,987.34x = 268,749,764.03
5. Step 5: Solve for x
   x = 268,749,764.03/13,987.34
6. Step 6: Final answer
   x = 19,213.79