Finding the Fourth Proportional to 1,231.68, 1,699.72 and 672.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,231.68 : 1,699.72 = 672.15 : x
2. Step 2: Convert to fraction form
   1,231.68/1,699.72 = 672.15/x
3. Step 3: Cross multiply
   1,231.68x = 1,699.72 × 672.15
4. Step 4: Simplify right side
   1,231.68x = 1,142,466.80
5. Step 5: Solve for x
   x = 1,142,466.80/1,231.68
6. Step 6: Final answer
   x = 927.57