Home / 685.87-1,028.50-425.86

Finding the Fourth Proportional to 685.87, 1,028.50 and 425.86

Calculator

Solution

The fourth proportional to 685.87, 1,028.50 and 425.86 is: 638.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.87 : 1,028.50 = 425.86 : x
  2. Step 2: Convert to fraction form
    685.87/1,028.50 = 425.86/x
  3. Step 3: Cross multiply
    685.87x = 1,028.50 × 425.86
  4. Step 4: Simplify right side
    685.87x = 437,993.37
  5. Step 5: Solve for x
    x = 437,993.37/685.87
  6. Step 6: Final answer
    x = 638.60

Related Problems

Find fourth proportional to 342.93, 514.25 and 212.93
Half scale
Find fourth proportional to 1,371.74, 2,057.00 and 851.72
Double scale
Find fourth proportional to 686.87, 1,030 and 426.86
Similar ratio
Find fourth proportional to 1,028.80, 1,542.75 and 638.79
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.