Finding the Fourth Proportional to 1,137.72, 1,570.06 and 672.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,137.72 : 1,570.06 = 672.20 : x
2. Step 2: Convert to fraction form
   1,137.72/1,570.06 = 672.20/x
3. Step 3: Cross multiply
   1,137.72x = 1,570.06 × 672.20
4. Step 4: Simplify right side
   1,137.72x = 1,055,394.33
5. Step 5: Solve for x
   x = 1,055,394.33/1,137.72
6. Step 6: Final answer
   x = 927.64