Finding the Fourth Proportional to 21,061.08, 31,591.01 and 8,578.01

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.08 : 31,591.01 = 8,578.01 : x
2. Step 2: Convert to fraction form
   21,061.08/31,591.01 = 8,578.01/x
3. Step 3: Cross multiply
   21,061.08x = 31,591.01 × 8,578.01
4. Step 4: Simplify right side
   21,061.08x = 270,988,090.25
5. Step 5: Solve for x
   x = 270,988,090.25/21,061.08
6. Step 6: Final answer
   x = 12,866.77