Finding the Fourth Proportional to 1,017.72, 1,526.42 and 287.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.72 : 1,526.42 = 287.36 : x
2. Step 2: Convert to fraction form
   1,017.72/1,526.42 = 287.36/x
3. Step 3: Cross multiply
   1,017.72x = 1,526.42 × 287.36
4. Step 4: Simplify right side
   1,017.72x = 438,632.05
5. Step 5: Solve for x
   x = 438,632.05/1,017.72
6. Step 6: Final answer
   x = 430.99