Finding the Fourth Proportional to 1,018.78, 1,405.29 and 888.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,018.78 : 1,405.29 = 888.10 : x
2. Step 2: Convert to fraction form
   1,018.78/1,405.29 = 888.10/x
3. Step 3: Cross multiply
   1,018.78x = 1,405.29 × 888.10
4. Step 4: Simplify right side
   1,018.78x = 1,248,038.05
5. Step 5: Solve for x
   x = 1,248,038.05/1,018.78
6. Step 6: Final answer
   x = 1,225.03