Finding the Fourth Proportional to 1,095.72, 1,643.59 and 315.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,095.72 : 1,643.59 = 315.79 : x
2. Step 2: Convert to fraction form
   1,095.72/1,643.59 = 315.79/x
3. Step 3: Cross multiply
   1,095.72x = 1,643.59 × 315.79
4. Step 4: Simplify right side
   1,095.72x = 519,029.29
5. Step 5: Solve for x
   x = 519,029.29/1,095.72
6. Step 6: Final answer
   x = 473.69