Finding the Fourth Proportional to 12,665.41, 18,987.86 and 5,275.42

Step by Step Solution

1. Step 1: Write the proportion equation
   12,665.41 : 18,987.86 = 5,275.42 : x
2. Step 2: Convert to fraction form
   12,665.41/18,987.86 = 5,275.42/x
3. Step 3: Cross multiply
   12,665.41x = 18,987.86 × 5,275.42
4. Step 4: Simplify right side
   12,665.41x = 100,168,902.12
5. Step 5: Solve for x
   x = 100,168,902.12/12,665.41
6. Step 6: Final answer
   x = 7,908.86