Finding the Fourth Proportional to 1,171.76, 1,616.89 and 647.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,171.76 : 1,616.89 = 647.70 : x
2. Step 2: Convert to fraction form
   1,171.76/1,616.89 = 647.70/x
3. Step 3: Cross multiply
   1,171.76x = 1,616.89 × 647.70
4. Step 4: Simplify right side
   1,171.76x = 1,047,259.65
5. Step 5: Solve for x
   x = 1,047,259.65/1,171.76
6. Step 6: Final answer
   x = 893.75