Home / 396.50-549.45-389.21

Finding the Fourth Proportional to 396.50, 549.45 and 389.21

Calculator

Solution

The fourth proportional to 396.50, 549.45 and 389.21 is: 539.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    396.50 : 549.45 = 389.21 : x
  2. Step 2: Convert to fraction form
    396.50/549.45 = 389.21/x
  3. Step 3: Cross multiply
    396.50x = 549.45 × 389.21
  4. Step 4: Simplify right side
    396.50x = 213,848.69
  5. Step 5: Solve for x
    x = 213,848.69/396.50
  6. Step 6: Final answer
    x = 539.35

Related Problems

Find fourth proportional to 198.25, 274.73 and 194.60
Half scale
Find fourth proportional to 792.99, 1,098.90 and 778.41
Double scale
Find fourth proportional to 397.50, 550.84 and 390.21
Similar ratio
Find fourth proportional to 594.74, 824.18 and 583.81
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.