Home / 25.68-38.64-20.88

Finding the Fourth Proportional to 25.68, 38.64 and 20.88

Calculator

Solution

The fourth proportional to 25.68, 38.64 and 20.88 is: 31.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    25.68 : 38.64 = 20.88 : x
  2. Step 2: Convert to fraction form
    25.68/38.64 = 20.88/x
  3. Step 3: Cross multiply
    25.68x = 38.64 × 20.88
  4. Step 4: Simplify right side
    25.68x = 806.80
  5. Step 5: Solve for x
    x = 806.80/25.68
  6. Step 6: Final answer
    x = 31.42

Related Problems

Find fourth proportional to 12.84, 19.32 and 10.44
Half scale
Find fourth proportional to 51.36, 77.28 and 41.76
Double scale
Find fourth proportional to 26.68, 40.14 and 21.88
Similar ratio
Find fourth proportional to 38.52, 57.96 and 31.32
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.