Finding the Fourth Proportional to 1,145.07, 1,580.22 and 647.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.07 : 1,580.22 = 647.72 : x
2. Step 2: Convert to fraction form
   1,145.07/1,580.22 = 647.72/x
3. Step 3: Cross multiply
   1,145.07x = 1,580.22 × 647.72
4. Step 4: Simplify right side
   1,145.07x = 1,023,540.10
5. Step 5: Solve for x
   x = 1,023,540.10/1,145.07
6. Step 6: Final answer
   x = 893.87