Finding the Fourth Proportional to 1,308.48, 1,961.76 and 1,128

Step by Step Solution

1. Step 1: Write the proportion equation
   1,308.48 : 1,961.76 = 1,128 : x
2. Step 2: Convert to fraction form
   1,308.48/1,961.76 = 1,128/x
3. Step 3: Cross multiply
   1,308.48x = 1,961.76 × 1,128
4. Step 4: Simplify right side
   1,308.48x = 2,212,865.28
5. Step 5: Solve for x
   x = 2,212,865.28/1,308.48
6. Step 6: Final answer
   x = 1,691.17