Finding the Fourth Proportional to 1,042.13, 1,438.17 and 570.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,042.13 : 1,438.17 = 570.05 : x
2. Step 2: Convert to fraction form
   1,042.13/1,438.17 = 570.05/x
3. Step 3: Cross multiply
   1,042.13x = 1,438.17 × 570.05
4. Step 4: Simplify right side
   1,042.13x = 819,828.81
5. Step 5: Solve for x
   x = 819,828.81/1,042.13
6. Step 6: Final answer
   x = 786.69