Finding the Fourth Proportional to 21,781.76, 32,665.50 and 6,987.15

Step by Step Solution

1. Step 1: Write the proportion equation
   21,781.76 : 32,665.50 = 6,987.15 : x
2. Step 2: Convert to fraction form
   21,781.76/32,665.50 = 6,987.15/x
3. Step 3: Cross multiply
   21,781.76x = 32,665.50 × 6,987.15
4. Step 4: Simplify right side
   21,781.76x = 228,238,748.33
5. Step 5: Solve for x
   x = 228,238,748.33/21,781.76
6. Step 6: Final answer
   x = 10,478.44