Finding the Fourth Proportional to 21,164.88, 31,719.83 and 8,670.74

Step by Step Solution

1. Step 1: Write the proportion equation
   21,164.88 : 31,719.83 = 8,670.74 : x
2. Step 2: Convert to fraction form
   21,164.88/31,719.83 = 8,670.74/x
3. Step 3: Cross multiply
   21,164.88x = 31,719.83 × 8,670.74
4. Step 4: Simplify right side
   21,164.88x = 275,034,196.82
5. Step 5: Solve for x
   x = 275,034,196.82/21,164.88
6. Step 6: Final answer
   x = 12,994.84