Finding the Fourth Proportional to 1,010.82, 1,516.22 and 280.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,010.82 : 1,516.22 = 280.39 : x
2. Step 2: Convert to fraction form
   1,010.82/1,516.22 = 280.39/x
3. Step 3: Cross multiply
   1,010.82x = 1,516.22 × 280.39
4. Step 4: Simplify right side
   1,010.82x = 425,123.94
5. Step 5: Solve for x
   x = 425,123.94/1,010.82
6. Step 6: Final answer
   x = 420.58