Finding the Fourth Proportional to 2,072.80, 3,111.21 and 977.92

Step by Step Solution

1. Step 1: Write the proportion equation
   2,072.80 : 3,111.21 = 977.92 : x
2. Step 2: Convert to fraction form
   2,072.80/3,111.21 = 977.92/x
3. Step 3: Cross multiply
   2,072.80x = 3,111.21 × 977.92
4. Step 4: Simplify right side
   2,072.80x = 3,042,514.48
5. Step 5: Solve for x
   x = 3,042,514.48/2,072.80
6. Step 6: Final answer
   x = 1,467.83