Finding the Fourth Proportional to 30,656.78, 42,323.70 and 19,911.25

Step by Step Solution

1. Step 1: Write the proportion equation
   30,656.78 : 42,323.70 = 19,911.25 : x
2. Step 2: Convert to fraction form
   30,656.78/42,323.70 = 19,911.25/x
3. Step 3: Cross multiply
   30,656.78x = 42,323.70 × 19,911.25
4. Step 4: Simplify right side
   30,656.78x = 842,717,460.45
5. Step 5: Solve for x
   x = 842,717,460.45/30,656.78
6. Step 6: Final answer
   x = 27,488.78