Finding the Fourth Proportional to 1,919.72, 2,651.30 and 1,221.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,919.72 : 2,651.30 = 1,221.52 : x
2. Step 2: Convert to fraction form
   1,919.72/2,651.30 = 1,221.52/x
3. Step 3: Cross multiply
   1,919.72x = 2,651.30 × 1,221.52
4. Step 4: Simplify right side
   1,919.72x = 3,238,615.98
5. Step 5: Solve for x
   x = 3,238,615.98/1,919.72
6. Step 6: Final answer
   x = 1,687.03