Finding the Fourth Proportional to 1,213.69, 1,674.75 and 689.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.69 : 1,674.75 = 689.71 : x
2. Step 2: Convert to fraction form
   1,213.69/1,674.75 = 689.71/x
3. Step 3: Cross multiply
   1,213.69x = 1,674.75 × 689.71
4. Step 4: Simplify right side
   1,213.69x = 1,155,091.82
5. Step 5: Solve for x
   x = 1,155,091.82/1,213.69
6. Step 6: Final answer
   x = 951.72