Finding the Fourth Proportional to 1,681.74, 2,320.72 and 935.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,681.74 : 2,320.72 = 935.76 : x
2. Step 2: Convert to fraction form
   1,681.74/2,320.72 = 935.76/x
3. Step 3: Cross multiply
   1,681.74x = 2,320.72 × 935.76
4. Step 4: Simplify right side
   1,681.74x = 2,171,643.31
5. Step 5: Solve for x
   x = 2,171,643.31/1,681.74
6. Step 6: Final answer
   x = 1,291.31