Finding the Fourth Proportional to 696.45, 1,039.89 and 678.00

Step by Step Solution

1. Step 1: Write the proportion equation
   696.45 : 1,039.89 = 678.00 : x
2. Step 2: Convert to fraction form
   696.45/1,039.89 = 678.00/x
3. Step 3: Cross multiply
   696.45x = 1,039.89 × 678.00
4. Step 4: Simplify right side
   696.45x = 705,039.27
5. Step 5: Solve for x
   x = 705,039.27/696.45
6. Step 6: Final answer
   x = 1,012.34