Finding the Fourth Proportional to 1,128.56, 1,690.80 and 1,060.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.56 : 1,690.80 = 1,060.78 : x
2. Step 2: Convert to fraction form
   1,128.56/1,690.80 = 1,060.78/x
3. Step 3: Cross multiply
   1,128.56x = 1,690.80 × 1,060.78
4. Step 4: Simplify right side
   1,128.56x = 1,793,566.82
5. Step 5: Solve for x
   x = 1,793,566.82/1,128.56
6. Step 6: Final answer
   x = 1,589.25