Finding the Fourth Proportional to 978.55, 1,465.54 and 771.69

Step by Step Solution

1. Step 1: Write the proportion equation
   978.55 : 1,465.54 = 771.69 : x
2. Step 2: Convert to fraction form
   978.55/1,465.54 = 771.69/x
3. Step 3: Cross multiply
   978.55x = 1,465.54 × 771.69
4. Step 4: Simplify right side
   978.55x = 1,130,950.47
5. Step 5: Solve for x
   x = 1,130,950.47/978.55
6. Step 6: Final answer
   x = 1,155.74