Home / 343.75-515.70-138.28

Finding the Fourth Proportional to 343.75, 515.70 and 138.28

Calculator

Solution

The fourth proportional to 343.75, 515.70 and 138.28 is: 207.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    343.75 : 515.70 = 138.28 : x
  2. Step 2: Convert to fraction form
    343.75/515.70 = 138.28/x
  3. Step 3: Cross multiply
    343.75x = 515.70 × 138.28
  4. Step 4: Simplify right side
    343.75x = 71,311.00
  5. Step 5: Solve for x
    x = 71,311.00/343.75
  6. Step 6: Final answer
    x = 207.45

Related Problems

Find fourth proportional to 171.88, 257.85 and 69.14
Half scale
Find fourth proportional to 687.50, 1,031.40 and 276.56
Double scale
Find fourth proportional to 344.75, 517.20 and 139.28
Similar ratio
Find fourth proportional to 515.63, 773.55 and 207.42
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.