Home / 154.21-212.69-123.09

Finding the Fourth Proportional to 154.21, 212.69 and 123.09

Calculator

Solution

The fourth proportional to 154.21, 212.69 and 123.09 is: 169.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.21 : 212.69 = 123.09 : x
  2. Step 2: Convert to fraction form
    154.21/212.69 = 123.09/x
  3. Step 3: Cross multiply
    154.21x = 212.69 × 123.09
  4. Step 4: Simplify right side
    154.21x = 26,178.95
  5. Step 5: Solve for x
    x = 26,178.95/154.21
  6. Step 6: Final answer
    x = 169.76

Related Problems

Find fourth proportional to 77.11, 106.35 and 61.54
Half scale
Find fourth proportional to 308.42, 425.38 and 246.17
Double scale
Find fourth proportional to 155.21, 214.07 and 124.09
Similar ratio
Find fourth proportional to 231.32, 319.04 and 184.63
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.