Home / 19.78-27.27-15.70

Finding the Fourth Proportional to 19.78, 27.27 and 15.70

Calculator

Solution

The fourth proportional to 19.78, 27.27 and 15.70 is: 21.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    19.78 : 27.27 = 15.70 : x
  2. Step 2: Convert to fraction form
    19.78/27.27 = 15.70/x
  3. Step 3: Cross multiply
    19.78x = 27.27 × 15.70
  4. Step 4: Simplify right side
    19.78x = 428.14
  5. Step 5: Solve for x
    x = 428.14/19.78
  6. Step 6: Final answer
    x = 21.65

Related Problems

Find fourth proportional to 9.89, 13.64 and 7.85
Half scale
Find fourth proportional to 39.56, 54.54 and 31.40
Double scale
Find fourth proportional to 20.78, 28.65 and 16.70
Similar ratio
Find fourth proportional to 29.67, 40.91 and 23.55
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.