Finding the Fourth Proportional to 21,079.83, 31,621.38 and 7,931.91

Step by Step Solution

1. Step 1: Write the proportion equation
   21,079.83 : 31,621.38 = 7,931.91 : x
2. Step 2: Convert to fraction form
   21,079.83/31,621.38 = 7,931.91/x
3. Step 3: Cross multiply
   21,079.83x = 31,621.38 × 7,931.91
4. Step 4: Simplify right side
   21,079.83x = 250,817,940.24
5. Step 5: Solve for x
   x = 250,817,940.24/21,079.83
6. Step 6: Final answer
   x = 11,898.48