Finding the Fourth Proportional to 1,323.18, 1,980.87 and 978.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,323.18 : 1,980.87 = 978.05 : x
2. Step 2: Convert to fraction form
   1,323.18/1,980.87 = 978.05/x
3. Step 3: Cross multiply
   1,323.18x = 1,980.87 × 978.05
4. Step 4: Simplify right side
   1,323.18x = 1,937,389.90
5. Step 5: Solve for x
   x = 1,937,389.90/1,323.18
6. Step 6: Final answer
   x = 1,464.20