Finding the Fourth Proportional to 39,111.15, 53,973.49 and 21,206.15

Step by Step Solution

1. Step 1: Write the proportion equation
   39,111.15 : 53,973.49 = 21,206.15 : x
2. Step 2: Convert to fraction form
   39,111.15/53,973.49 = 21,206.15/x
3. Step 3: Cross multiply
   39,111.15x = 53,973.49 × 21,206.15
4. Step 4: Simplify right side
   39,111.15x = 1,144,570,147.84
5. Step 5: Solve for x
   x = 1,144,570,147.84/39,111.15
6. Step 6: Final answer
   x = 29,264.55