Finding the Fourth Proportional to 1,006.91, 1,389.54 and 608.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,006.91 : 1,389.54 = 608.60 : x
2. Step 2: Convert to fraction form
   1,006.91/1,389.54 = 608.60/x
3. Step 3: Cross multiply
   1,006.91x = 1,389.54 × 608.60
4. Step 4: Simplify right side
   1,006.91x = 845,667.10
5. Step 5: Solve for x
   x = 845,667.10/1,006.91
6. Step 6: Final answer
   x = 839.87