Finding the Fourth Proportional to 13,642.91, 18,821.39 and 7,818.93

Step by Step Solution

1. Step 1: Write the proportion equation
   13,642.91 : 18,821.39 = 7,818.93 : x
2. Step 2: Convert to fraction form
   13,642.91/18,821.39 = 7,818.93/x
3. Step 3: Cross multiply
   13,642.91x = 18,821.39 × 7,818.93
4. Step 4: Simplify right side
   13,642.91x = 147,163,091.82
5. Step 5: Solve for x
   x = 147,163,091.82/13,642.91
6. Step 6: Final answer
   x = 10,786.78