Finding the Fourth Proportional to 1,279.92, 1,920.42 and 549.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,279.92 : 1,920.42 = 549.30 : x
2. Step 2: Convert to fraction form
   1,279.92/1,920.42 = 549.30/x
3. Step 3: Cross multiply
   1,279.92x = 1,920.42 × 549.30
4. Step 4: Simplify right side
   1,279.92x = 1,054,886.71
5. Step 5: Solve for x
   x = 1,054,886.71/1,279.92
6. Step 6: Final answer
   x = 824.18