Finding the Fourth Proportional to 21,145.86, 31,719.31 and 7,106.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,145.86 : 31,719.31 = 7,106.09 : x
2. Step 2: Convert to fraction form
   21,145.86/31,719.31 = 7,106.09/x
3. Step 3: Cross multiply
   21,145.86x = 31,719.31 × 7,106.09
4. Step 4: Simplify right side
   21,145.86x = 225,400,271.60
5. Step 5: Solve for x
   x = 225,400,271.60/21,145.86
6. Step 6: Final answer
   x = 10,659.31