Finding the Fourth Proportional to 30,947.33, 42,742.49 and 20,858.38

Step by Step Solution

1. Step 1: Write the proportion equation
   30,947.33 : 42,742.49 = 20,858.38 : x
2. Step 2: Convert to fraction form
   30,947.33/42,742.49 = 20,858.38/x
3. Step 3: Cross multiply
   30,947.33x = 42,742.49 × 20,858.38
4. Step 4: Simplify right side
   30,947.33x = 891,538,887.42
5. Step 5: Solve for x
   x = 891,538,887.42/30,947.33
6. Step 6: Final answer
   x = 28,808.26