Finding the Fourth Proportional to 31,725.07, 43,780.59 and 18,978.79

Step by Step Solution

1. Step 1: Write the proportion equation
   31,725.07 : 43,780.59 = 18,978.79 : x
2. Step 2: Convert to fraction form
   31,725.07/43,780.59 = 18,978.79/x
3. Step 3: Cross multiply
   31,725.07x = 43,780.59 × 18,978.79
4. Step 4: Simplify right side
   31,725.07x = 830,902,514.23
5. Step 5: Solve for x
   x = 830,902,514.23/31,725.07
6. Step 6: Final answer
   x = 26,190.72