Finding the Fourth Proportional to 13,216.71, 18,237.79 and 7,911.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,216.71 : 18,237.79 = 7,911.42 : x
2. Step 2: Convert to fraction form
   13,216.71/18,237.79 = 7,911.42/x
3. Step 3: Cross multiply
   13,216.71x = 18,237.79 × 7,911.42
4. Step 4: Simplify right side
   13,216.71x = 144,286,816.56
5. Step 5: Solve for x
   x = 144,286,816.56/13,216.71
6. Step 6: Final answer
   x = 10,917.00