Finding the Fourth Proportional to 1,009.31, 1,514.00 and 278.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,009.31 : 1,514.00 = 278.89 : x
2. Step 2: Convert to fraction form
   1,009.31/1,514.00 = 278.89/x
3. Step 3: Cross multiply
   1,009.31x = 1,514.00 × 278.89
4. Step 4: Simplify right side
   1,009.31x = 422,230.50
5. Step 5: Solve for x
   x = 422,230.50/1,009.31
6. Step 6: Final answer
   x = 418.34