Finding the Fourth Proportional to 978.48, 1,466.10 and 688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   978.48 : 1,466.10 = 688.50 : x
2. Step 2: Convert to fraction form
   978.48/1,466.10 = 688.50/x
3. Step 3: Cross multiply
   978.48x = 1,466.10 × 688.50
4. Step 4: Simplify right side
   978.48x = 1,009,409.85
5. Step 5: Solve for x
   x = 1,009,409.85/978.48
6. Step 6: Final answer
   x = 1,031.61