Home / 154.34-231.30-85.80

Finding the Fourth Proportional to 154.34, 231.30 and 85.80

Calculator

Solution

The fourth proportional to 154.34, 231.30 and 85.80 is: 128.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.34 : 231.30 = 85.80 : x
  2. Step 2: Convert to fraction form
    154.34/231.30 = 85.80/x
  3. Step 3: Cross multiply
    154.34x = 231.30 × 85.80
  4. Step 4: Simplify right side
    154.34x = 19,845.54
  5. Step 5: Solve for x
    x = 19,845.54/154.34
  6. Step 6: Final answer
    x = 128.58

Related Problems

Find fourth proportional to 77.17, 115.65 and 42.90
Half scale
Find fourth proportional to 308.68, 462.60 and 171.60
Double scale
Find fourth proportional to 155.34, 232.80 and 86.80
Similar ratio
Find fourth proportional to 231.51, 346.95 and 128.70
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.