Finding the Fourth Proportional to 2,101.56, 2,900.79 and 1,217.58

Step by Step Solution

1. Step 1: Write the proportion equation
   2,101.56 : 2,900.79 = 1,217.58 : x
2. Step 2: Convert to fraction form
   2,101.56/2,900.79 = 1,217.58/x
3. Step 3: Cross multiply
   2,101.56x = 2,900.79 × 1,217.58
4. Step 4: Simplify right side
   2,101.56x = 3,531,943.89
5. Step 5: Solve for x
   x = 3,531,943.89/2,101.56
6. Step 6: Final answer
   x = 1,680.63