Finding the Fourth Proportional to 21,148.36, 31,726.20 and 7,109.76

Step by Step Solution

1. Step 1: Write the proportion equation
   21,148.36 : 31,726.20 = 7,109.76 : x
2. Step 2: Convert to fraction form
   21,148.36/31,726.20 = 7,109.76/x
3. Step 3: Cross multiply
   21,148.36x = 31,726.20 × 7,109.76
4. Step 4: Simplify right side
   21,148.36x = 225,565,667.71
5. Step 5: Solve for x
   x = 225,565,667.71/21,148.36
6. Step 6: Final answer
   x = 10,665.87