Finding the Fourth Proportional to 21,389.56, 31,871.15 and 19,061.80

Step by Step Solution

1. Step 1: Write the proportion equation
   21,389.56 : 31,871.15 = 19,061.80 : x
2. Step 2: Convert to fraction form
   21,389.56/31,871.15 = 19,061.80/x
3. Step 3: Cross multiply
   21,389.56x = 31,871.15 × 19,061.80
4. Step 4: Simplify right side
   21,389.56x = 607,521,487.07
5. Step 5: Solve for x
   x = 607,521,487.07/21,389.56
6. Step 6: Final answer
   x = 28,402.71