Finding the Fourth Proportional to 978.69, 1,468.58 and 806.88

Step by Step Solution

1. Step 1: Write the proportion equation
   978.69 : 1,468.58 = 806.88 : x
2. Step 2: Convert to fraction form
   978.69/1,468.58 = 806.88/x
3. Step 3: Cross multiply
   978.69x = 1,468.58 × 806.88
4. Step 4: Simplify right side
   978.69x = 1,184,963.80
5. Step 5: Solve for x
   x = 1,184,963.80/978.69
6. Step 6: Final answer
   x = 1,210.77