Home / 424.21-636.11-259.78

Finding the Fourth Proportional to 424.21, 636.11 and 259.78

Calculator

Solution

The fourth proportional to 424.21, 636.11 and 259.78 is: 389.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    424.21 : 636.11 = 259.78 : x
  2. Step 2: Convert to fraction form
    424.21/636.11 = 259.78/x
  3. Step 3: Cross multiply
    424.21x = 636.11 × 259.78
  4. Step 4: Simplify right side
    424.21x = 165,246.74
  5. Step 5: Solve for x
    x = 165,246.74/424.21
  6. Step 6: Final answer
    x = 389.54

Related Problems

Find fourth proportional to 212.10, 318.05 and 129.89
Half scale
Find fourth proportional to 848.42, 1,272.22 and 519.56
Double scale
Find fourth proportional to 425.21, 637.61 and 260.78
Similar ratio
Find fourth proportional to 636.31, 954.16 and 389.67
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.