Finding the Fourth Proportional to 1,999.21, 2,758.89 and 1,115

Step by Step Solution

1. Step 1: Write the proportion equation
   1,999.21 : 2,758.89 = 1,115 : x
2. Step 2: Convert to fraction form
   1,999.21/2,758.89 = 1,115/x
3. Step 3: Cross multiply
   1,999.21x = 2,758.89 × 1,115
4. Step 4: Simplify right side
   1,999.21x = 3,076,162.35
5. Step 5: Solve for x
   x = 3,076,162.35/1,999.21
6. Step 6: Final answer
   x = 1,538.69