Finding the Fourth Proportional to 2,171.77, 2,997.42 and 1,287.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.77 : 2,997.42 = 1,287.88 : x
2. Step 2: Convert to fraction form
   2,171.77/2,997.42 = 1,287.88/x
3. Step 3: Cross multiply
   2,171.77x = 2,997.42 × 1,287.88
4. Step 4: Simplify right side
   2,171.77x = 3,860,317.27
5. Step 5: Solve for x
   x = 3,860,317.27/2,171.77
6. Step 6: Final answer
   x = 1,777.50