Finding the Fourth Proportional to 1,170.72, 1,615.61 and 646.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,170.72 : 1,615.61 = 646.72 : x
2. Step 2: Convert to fraction form
   1,170.72/1,615.61 = 646.72/x
3. Step 3: Cross multiply
   1,170.72x = 1,615.61 × 646.72
4. Step 4: Simplify right side
   1,170.72x = 1,044,844.88
5. Step 5: Solve for x
   x = 1,044,844.88/1,170.72
6. Step 6: Final answer
   x = 892.48