Finding the Fourth Proportional to 1,005.93, 1,507.89 and 485.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.93 : 1,507.89 = 485.78 : x
2. Step 2: Convert to fraction form
   1,005.93/1,507.89 = 485.78/x
3. Step 3: Cross multiply
   1,005.93x = 1,507.89 × 485.78
4. Step 4: Simplify right side
   1,005.93x = 732,502.80
5. Step 5: Solve for x
   x = 732,502.80/1,005.93
6. Step 6: Final answer
   x = 728.18