Finding the Fourth Proportional to 1,210.47, 1,670.48 and 686.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,210.47 : 1,670.48 = 686.52 : x
2. Step 2: Convert to fraction form
   1,210.47/1,670.48 = 686.52/x
3. Step 3: Cross multiply
   1,210.47x = 1,670.48 × 686.52
4. Step 4: Simplify right side
   1,210.47x = 1,146,814.50
5. Step 5: Solve for x
   x = 1,146,814.50/1,210.47
6. Step 6: Final answer
   x = 947.41