Finding the Fourth Proportional to 3,870.80, 5,808.72 and 1,680.56

Step by Step Solution

1. Step 1: Write the proportion equation
   3,870.80 : 5,808.72 = 1,680.56 : x
2. Step 2: Convert to fraction form
   3,870.80/5,808.72 = 1,680.56/x
3. Step 3: Cross multiply
   3,870.80x = 5,808.72 × 1,680.56
4. Step 4: Simplify right side
   3,870.80x = 9,761,902.48
5. Step 5: Solve for x
   x = 9,761,902.48/3,870.80
6. Step 6: Final answer
   x = 2,521.93