Finding the Fourth Proportional to 1,328.76, 1,991.34 and 1,289.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,328.76 : 1,991.34 = 1,289.34 : x
2. Step 2: Convert to fraction form
   1,328.76/1,991.34 = 1,289.34/x
3. Step 3: Cross multiply
   1,328.76x = 1,991.34 × 1,289.34
4. Step 4: Simplify right side
   1,328.76x = 2,567,514.32
5. Step 5: Solve for x
   x = 2,567,514.32/1,328.76
6. Step 6: Final answer
   x = 1,932.26