Finding the Fourth Proportional to 2,139.84, 3,210.75 and 1,164.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.84 : 3,210.75 = 1,164.78 : x
2. Step 2: Convert to fraction form
   2,139.84/3,210.75 = 1,164.78/x
3. Step 3: Cross multiply
   2,139.84x = 3,210.75 × 1,164.78
4. Step 4: Simplify right side
   2,139.84x = 3,739,817.39
5. Step 5: Solve for x
   x = 3,739,817.39/2,139.84
6. Step 6: Final answer
   x = 1,747.71