Finding the Fourth Proportional to 2,870.88, 4,306.33 and 1,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,870.88 : 4,306.33 = 1,139.50 : x
2. Step 2: Convert to fraction form
   2,870.88/4,306.33 = 1,139.50/x
3. Step 3: Cross multiply
   2,870.88x = 4,306.33 × 1,139.50
4. Step 4: Simplify right side
   2,870.88x = 4,907,069.84
5. Step 5: Solve for x
   x = 4,907,069.84/2,870.88
6. Step 6: Final answer
   x = 1,709.26