Finding the Fourth Proportional to 20,958.39, 31,451.69 and 7,810.76

Step by Step Solution

1. Step 1: Write the proportion equation
   20,958.39 : 31,451.69 = 7,810.76 : x
2. Step 2: Convert to fraction form
   20,958.39/31,451.69 = 7,810.76/x
3. Step 3: Cross multiply
   20,958.39x = 31,451.69 × 7,810.76
4. Step 4: Simplify right side
   20,958.39x = 245,661,700.34
5. Step 5: Solve for x
   x = 245,661,700.34/20,958.39
6. Step 6: Final answer
   x = 11,721.40