Finding the Fourth Proportional to 1,012.34, 1,389.56 and 899.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.34 : 1,389.56 = 899.34 : x
2. Step 2: Convert to fraction form
   1,012.34/1,389.56 = 899.34/x
3. Step 3: Cross multiply
   1,012.34x = 1,389.56 × 899.34
4. Step 4: Simplify right side
   1,012.34x = 1,249,686.89
5. Step 5: Solve for x
   x = 1,249,686.89/1,012.34
6. Step 6: Final answer
   x = 1,234.45