Finding the Fourth Proportional to 1,128.33, 1,690.88 and 543.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.33 : 1,690.88 = 543.15 : x
2. Step 2: Convert to fraction form
   1,128.33/1,690.88 = 543.15/x
3. Step 3: Cross multiply
   1,128.33x = 1,690.88 × 543.15
4. Step 4: Simplify right side
   1,128.33x = 918,398.76
5. Step 5: Solve for x
   x = 918,398.76/1,128.33
6. Step 6: Final answer
   x = 813.95