Finding the Fourth Proportional to 39,783.33, 54,899.89 and 21,878.33

Step by Step Solution

1. Step 1: Write the proportion equation
   39,783.33 : 54,899.89 = 21,878.33 : x
2. Step 2: Convert to fraction form
   39,783.33/54,899.89 = 21,878.33/x
3. Step 3: Cross multiply
   39,783.33x = 54,899.89 × 21,878.33
4. Step 4: Simplify right side
   39,783.33x = 1,201,117,965.08
5. Step 5: Solve for x
   x = 1,201,117,965.08/39,783.33
6. Step 6: Final answer
   x = 30,191.49