Finding the Fourth Proportional to 2,186.34, 3,279.78 and 647.34

Step by Step Solution

1. Step 1: Write the proportion equation
   2,186.34 : 3,279.78 = 647.34 : x
2. Step 2: Convert to fraction form
   2,186.34/3,279.78 = 647.34/x
3. Step 3: Cross multiply
   2,186.34x = 3,279.78 × 647.34
4. Step 4: Simplify right side
   2,186.34x = 2,123,132.79
5. Step 5: Solve for x
   x = 2,123,132.79/2,186.34
6. Step 6: Final answer
   x = 971.09