Finding the Fourth Proportional to 1,288.72, 1,933.16 and 351.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.72 : 1,933.16 = 351.80 : x
2. Step 2: Convert to fraction form
   1,288.72/1,933.16 = 351.80/x
3. Step 3: Cross multiply
   1,288.72x = 1,933.16 × 351.80
4. Step 4: Simplify right side
   1,288.72x = 680,085.69
5. Step 5: Solve for x
   x = 680,085.69/1,288.72
6. Step 6: Final answer
   x = 527.72