Finding the Fourth Proportional to 1,131.39, 1,692.56 and 978.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.39 : 1,692.56 = 978.96 : x
2. Step 2: Convert to fraction form
   1,131.39/1,692.56 = 978.96/x
3. Step 3: Cross multiply
   1,131.39x = 1,692.56 × 978.96
4. Step 4: Simplify right side
   1,131.39x = 1,656,943.64
5. Step 5: Solve for x
   x = 1,656,943.64/1,131.39
6. Step 6: Final answer
   x = 1,464.52