Finding the Fourth Proportional to 2,128.35, 2,937.69 and 1,289.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.35 : 2,937.69 = 1,289.10 : x
2. Step 2: Convert to fraction form
   2,128.35/2,937.69 = 1,289.10/x
3. Step 3: Cross multiply
   2,128.35x = 2,937.69 × 1,289.10
4. Step 4: Simplify right side
   2,128.35x = 3,786,976.18
5. Step 5: Solve for x
   x = 3,786,976.18/2,128.35
6. Step 6: Final answer
   x = 1,779.30