Home / 13.61-20.40-6

Finding the Fourth Proportional to 13.61, 20.40 and 6

Calculator

Solution

The fourth proportional to 13.61, 20.40 and 6 is: 9.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.61 : 20.40 = 6 : x
  2. Step 2: Convert to fraction form
    13.61/20.40 = 6/x
  3. Step 3: Cross multiply
    13.61x = 20.40 × 6
  4. Step 4: Simplify right side
    13.61x = 122.40
  5. Step 5: Solve for x
    x = 122.40/13.61
  6. Step 6: Final answer
    x = 9.00

Related Problems

Find fourth proportional to 6.80, 10.20 and 3
Half scale
Find fourth proportional to 27.21, 40.80 and 12
Double scale
Find fourth proportional to 14.61, 21.90 and 7
Similar ratio
Find fourth proportional to 20.41, 30.60 and 9
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.