Finding the Fourth Proportional to 1,009.01, 1,513.52 and 278.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,009.01 : 1,513.52 = 278.69 : x
2. Step 2: Convert to fraction form
   1,009.01/1,513.52 = 278.69/x
3. Step 3: Cross multiply
   1,009.01x = 1,513.52 × 278.69
4. Step 4: Simplify right side
   1,009.01x = 421,802.89
5. Step 5: Solve for x
   x = 421,802.89/1,009.01
6. Step 6: Final answer
   x = 418.04