Home / 135.93-204.05-81.21

Finding the Fourth Proportional to 135.93, 204.05 and 81.21

Calculator

Solution

The fourth proportional to 135.93, 204.05 and 81.21 is: 121.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.93 : 204.05 = 81.21 : x
  2. Step 2: Convert to fraction form
    135.93/204.05 = 81.21/x
  3. Step 3: Cross multiply
    135.93x = 204.05 × 81.21
  4. Step 4: Simplify right side
    135.93x = 16,570.49
  5. Step 5: Solve for x
    x = 16,570.49/135.93
  6. Step 6: Final answer
    x = 121.90

Related Problems

Find fourth proportional to 67.97, 102.02 and 40.61
Half scale
Find fourth proportional to 271.86, 408.09 and 162.42
Double scale
Find fourth proportional to 136.93, 205.55 and 82.21
Similar ratio
Find fourth proportional to 203.90, 306.07 and 121.82
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.