Finding the Fourth Proportional to 1,985.71, 2,740.29 and 1,288.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,985.71 : 2,740.29 = 1,288.30 : x
2. Step 2: Convert to fraction form
   1,985.71/2,740.29 = 1,288.30/x
3. Step 3: Cross multiply
   1,985.71x = 2,740.29 × 1,288.30
4. Step 4: Simplify right side
   1,985.71x = 3,530,315.61
5. Step 5: Solve for x
   x = 3,530,315.61/1,985.71
6. Step 6: Final answer
   x = 1,777.86