Finding the Fourth Proportional to 1,171.61, 1,616.82 and 647.64

Step by Step Solution

1. Step 1: Write the proportion equation
   1,171.61 : 1,616.82 = 647.64 : x
2. Step 2: Convert to fraction form
   1,171.61/1,616.82 = 647.64/x
3. Step 3: Cross multiply
   1,171.61x = 1,616.82 × 647.64
4. Step 4: Simplify right side
   1,171.61x = 1,047,117.30
5. Step 5: Solve for x
   x = 1,047,117.30/1,171.61
6. Step 6: Final answer
   x = 893.74