Finding the Fourth Proportional to 15,648.21, 21,594.45 and 8,478.09

Step by Step Solution

1. Step 1: Write the proportion equation
   15,648.21 : 21,594.45 = 8,478.09 : x
2. Step 2: Convert to fraction form
   15,648.21/21,594.45 = 8,478.09/x
3. Step 3: Cross multiply
   15,648.21x = 21,594.45 × 8,478.09
4. Step 4: Simplify right side
   15,648.21x = 183,079,690.60
5. Step 5: Solve for x
   x = 183,079,690.60/15,648.21
6. Step 6: Final answer
   x = 11,699.72