Finding the Fourth Proportional to 21,105.58, 31,642.64 and 7,057.30

Step by Step Solution

1. Step 1: Write the proportion equation
   21,105.58 : 31,642.64 = 7,057.30 : x
2. Step 2: Convert to fraction form
   21,105.58/31,642.64 = 7,057.30/x
3. Step 3: Cross multiply
   21,105.58x = 31,642.64 × 7,057.30
4. Step 4: Simplify right side
   21,105.58x = 223,311,603.27
5. Step 5: Solve for x
   x = 223,311,603.27/21,105.58
6. Step 6: Final answer
   x = 10,580.69