Finding the Fourth Proportional to 1,288.72, 1,931.48 and 672.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.72 : 1,931.48 = 672.10 : x
2. Step 2: Convert to fraction form
   1,288.72/1,931.48 = 672.10/x
3. Step 3: Cross multiply
   1,288.72x = 1,931.48 × 672.10
4. Step 4: Simplify right side
   1,288.72x = 1,298,147.71
5. Step 5: Solve for x
   x = 1,298,147.71/1,288.72
6. Step 6: Final answer
   x = 1,007.32