Finding the Fourth Proportional to 13,719.60, 18,931.59 and 10,136.43

Step by Step Solution

1. Step 1: Write the proportion equation
   13,719.60 : 18,931.59 = 10,136.43 : x
2. Step 2: Convert to fraction form
   13,719.60/18,931.59 = 10,136.43/x
3. Step 3: Cross multiply
   13,719.60x = 18,931.59 × 10,136.43
4. Step 4: Simplify right side
   13,719.60x = 191,898,736.82
5. Step 5: Solve for x
   x = 191,898,736.82/13,719.60
6. Step 6: Final answer
   x = 13,987.20