Finding the Fourth Proportional to 13,536.43, 18,672.78 and 7,870.55

Step by Step Solution

1. Step 1: Write the proportion equation
   13,536.43 : 18,672.78 = 7,870.55 : x
2. Step 2: Convert to fraction form
   13,536.43/18,672.78 = 7,870.55/x
3. Step 3: Cross multiply
   13,536.43x = 18,672.78 × 7,870.55
4. Step 4: Simplify right side
   13,536.43x = 146,965,068.33
5. Step 5: Solve for x
   x = 146,965,068.33/13,536.43
6. Step 6: Final answer
   x = 10,857.00