Finding the Fourth Proportional to 21,971.98, 30,320.68 and 12,412.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,971.98 : 30,320.68 = 12,412.31 : x
2. Step 2: Convert to fraction form
   21,971.98/30,320.68 = 12,412.31/x
3. Step 3: Cross multiply
   21,971.98x = 30,320.68 × 12,412.31
4. Step 4: Simplify right side
   21,971.98x = 376,349,617.51
5. Step 5: Solve for x
   x = 376,349,617.51/21,971.98
6. Step 6: Final answer
   x = 17,128.62