Finding the Fourth Proportional to 2,077.16, 3,115.76 and 978.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,077.16 : 3,115.76 = 978.40 : x
2. Step 2: Convert to fraction form
   2,077.16/3,115.76 = 978.40/x
3. Step 3: Cross multiply
   2,077.16x = 3,115.76 × 978.40
4. Step 4: Simplify right side
   2,077.16x = 3,048,459.58
5. Step 5: Solve for x
   x = 3,048,459.58/2,077.16
6. Step 6: Final answer
   x = 1,467.61