Home / 214.52-321.78-86.28

Finding the Fourth Proportional to 214.52, 321.78 and 86.28

Calculator

Solution

The fourth proportional to 214.52, 321.78 and 86.28 is: 129.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    214.52 : 321.78 = 86.28 : x
  2. Step 2: Convert to fraction form
    214.52/321.78 = 86.28/x
  3. Step 3: Cross multiply
    214.52x = 321.78 × 86.28
  4. Step 4: Simplify right side
    214.52x = 27,763.18
  5. Step 5: Solve for x
    x = 27,763.18/214.52
  6. Step 6: Final answer
    x = 129.42

Related Problems

Find fourth proportional to 107.26, 160.89 and 43.14
Half scale
Find fourth proportional to 429.04, 643.56 and 172.56
Double scale
Find fourth proportional to 215.52, 323.28 and 87.28
Similar ratio
Find fourth proportional to 321.78, 482.67 and 129.42
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.