Finding the Fourth Proportional to 2,139.48, 3,208.59 and 906.86

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.48 : 3,208.59 = 906.86 : x
2. Step 2: Convert to fraction form
   2,139.48/3,208.59 = 906.86/x
3. Step 3: Cross multiply
   2,139.48x = 3,208.59 × 906.86
4. Step 4: Simplify right side
   2,139.48x = 2,909,749.95
5. Step 5: Solve for x
   x = 2,909,749.95/2,139.48
6. Step 6: Final answer
   x = 1,360.03