Home / 404.20-557.69-256.78

Finding the Fourth Proportional to 404.20, 557.69 and 256.78

Calculator

Solution

The fourth proportional to 404.20, 557.69 and 256.78 is: 354.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    404.20 : 557.69 = 256.78 : x
  2. Step 2: Convert to fraction form
    404.20/557.69 = 256.78/x
  3. Step 3: Cross multiply
    404.20x = 557.69 × 256.78
  4. Step 4: Simplify right side
    404.20x = 143,203.64
  5. Step 5: Solve for x
    x = 143,203.64/404.20
  6. Step 6: Final answer
    x = 354.29

Related Problems

Find fourth proportional to 202.10, 278.85 and 128.39
Half scale
Find fourth proportional to 808.40, 1,115.38 and 513.56
Double scale
Find fourth proportional to 405.20, 559.07 and 257.78
Similar ratio
Find fourth proportional to 606.30, 836.54 and 385.17
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.