Finding the Fourth Proportional to 1,677.69, 2,315.24 and 931.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,677.69 : 2,315.24 = 931.72 : x
2. Step 2: Convert to fraction form
   1,677.69/2,315.24 = 931.72/x
3. Step 3: Cross multiply
   1,677.69x = 2,315.24 × 931.72
4. Step 4: Simplify right side
   1,677.69x = 2,157,143.69
5. Step 5: Solve for x
   x = 2,157,143.69/1,677.69
6. Step 6: Final answer
   x = 1,285.78