Finding the Fourth Proportional to 39,870.12, 55,020.51 and 21,964.71

Step by Step Solution

1. Step 1: Write the proportion equation
   39,870.12 : 55,020.51 = 21,964.71 : x
2. Step 2: Convert to fraction form
   39,870.12/55,020.51 = 21,964.71/x
3. Step 3: Cross multiply
   39,870.12x = 55,020.51 × 21,964.71
4. Step 4: Simplify right side
   39,870.12x = 1,208,509,546.20
5. Step 5: Solve for x
   x = 1,208,509,546.20/39,870.12
6. Step 6: Final answer
   x = 30,311.16