Finding the Fourth Proportional to 2,101.90, 2,899.98 and 1,217.59

Step by Step Solution

1. Step 1: Write the proportion equation
   2,101.90 : 2,899.98 = 1,217.59 : x
2. Step 2: Convert to fraction form
   2,101.90/2,899.98 = 1,217.59/x
3. Step 3: Cross multiply
   2,101.90x = 2,899.98 × 1,217.59
4. Step 4: Simplify right side
   2,101.90x = 3,530,986.65
5. Step 5: Solve for x
   x = 3,530,986.65/2,101.90
6. Step 6: Final answer
   x = 1,679.90