Home / 400.80-601.68-256.80

Finding the Fourth Proportional to 400.80, 601.68 and 256.80

Calculator

Solution

The fourth proportional to 400.80, 601.68 and 256.80 is: 385.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    400.80 : 601.68 = 256.80 : x
  2. Step 2: Convert to fraction form
    400.80/601.68 = 256.80/x
  3. Step 3: Cross multiply
    400.80x = 601.68 × 256.80
  4. Step 4: Simplify right side
    400.80x = 154,511.42
  5. Step 5: Solve for x
    x = 154,511.42/400.80
  6. Step 6: Final answer
    x = 385.51

Related Problems

Find fourth proportional to 200.40, 300.84 and 128.40
Half scale
Find fourth proportional to 801.60, 1,203.36 and 513.60
Double scale
Find fourth proportional to 401.80, 603.18 and 257.80
Similar ratio
Find fourth proportional to 601.20, 902.52 and 385.20
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.