Home / 380.78-571.18-137.30

Finding the Fourth Proportional to 380.78, 571.18 and 137.30

Calculator

Solution

The fourth proportional to 380.78, 571.18 and 137.30 is: 205.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.78 : 571.18 = 137.30 : x
  2. Step 2: Convert to fraction form
    380.78/571.18 = 137.30/x
  3. Step 3: Cross multiply
    380.78x = 571.18 × 137.30
  4. Step 4: Simplify right side
    380.78x = 78,423.01
  5. Step 5: Solve for x
    x = 78,423.01/380.78
  6. Step 6: Final answer
    x = 205.95

Related Problems

Find fourth proportional to 190.39, 285.59 and 68.65
Half scale
Find fourth proportional to 761.56, 1,142.36 and 274.60
Double scale
Find fourth proportional to 381.78, 572.68 and 138.30
Similar ratio
Find fourth proportional to 571.17, 856.77 and 205.95
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.