Finding the Fourth Proportional to 1,131.14, 1,692.18 and 978.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,131.14 : 1,692.18 = 978.70 : x
2. Step 2: Convert to fraction form
   1,131.14/1,692.18 = 978.70/x
3. Step 3: Cross multiply
   1,131.14x = 1,692.18 × 978.70
4. Step 4: Simplify right side
   1,131.14x = 1,656,136.57
5. Step 5: Solve for x
   x = 1,656,136.57/1,131.14
6. Step 6: Final answer
   x = 1,464.13