Finding the Fourth Proportional to 21,289.74, 31,920.71 and 10,196.07

Step by Step Solution

1. Step 1: Write the proportion equation
   21,289.74 : 31,920.71 = 10,196.07 : x
2. Step 2: Convert to fraction form
   21,289.74/31,920.71 = 10,196.07/x
3. Step 3: Cross multiply
   21,289.74x = 31,920.71 × 10,196.07
4. Step 4: Simplify right side
   21,289.74x = 325,465,742.63
5. Step 5: Solve for x
   x = 325,465,742.63/21,289.74
6. Step 6: Final answer
   x = 15,287.45