Home / 80-120.05-31.91

Finding the Fourth Proportional to 80, 120.05 and 31.91

Calculator

Solution

The fourth proportional to 80, 120.05 and 31.91 is: 47.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    80 : 120.05 = 31.91 : x
  2. Step 2: Convert to fraction form
    80/120.05 = 31.91/x
  3. Step 3: Cross multiply
    80x = 120.05 × 31.91
  4. Step 4: Simplify right side
    80x = 3,830.80
  5. Step 5: Solve for x
    x = 3,830.80/80
  6. Step 6: Final answer
    x = 47.88

Related Problems

Find fourth proportional to 40, 60.03 and 15.96
Half scale
Find fourth proportional to 160, 240.10 and 63.82
Double scale
Find fourth proportional to 81, 121.55 and 32.91
Similar ratio
Find fourth proportional to 120, 180.08 and 47.87
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.