Home / 67.20-100.72-38.31

Finding the Fourth Proportional to 67.20, 100.72 and 38.31

Calculator

Solution

The fourth proportional to 67.20, 100.72 and 38.31 is: 57.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    67.20 : 100.72 = 38.31 : x
  2. Step 2: Convert to fraction form
    67.20/100.72 = 38.31/x
  3. Step 3: Cross multiply
    67.20x = 100.72 × 38.31
  4. Step 4: Simplify right side
    67.20x = 3,858.58
  5. Step 5: Solve for x
    x = 3,858.58/67.20
  6. Step 6: Final answer
    x = 57.42

Related Problems

Find fourth proportional to 33.60, 50.36 and 19.16
Half scale
Find fourth proportional to 134.40, 201.44 and 76.62
Double scale
Find fourth proportional to 68.20, 102.22 and 39.31
Similar ratio
Find fourth proportional to 100.80, 151.08 and 57.47
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.