Home / 36.21-54.31-21

Finding the Fourth Proportional to 36.21, 54.31 and 21

Calculator

Solution

The fourth proportional to 36.21, 54.31 and 21 is: 31.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    36.21 : 54.31 = 21 : x
  2. Step 2: Convert to fraction form
    36.21/54.31 = 21/x
  3. Step 3: Cross multiply
    36.21x = 54.31 × 21
  4. Step 4: Simplify right side
    36.21x = 1,140.51
  5. Step 5: Solve for x
    x = 1,140.51/36.21
  6. Step 6: Final answer
    x = 31.50

Related Problems

Find fourth proportional to 18.11, 27.16 and 10.50
Half scale
Find fourth proportional to 72.42, 108.62 and 42
Double scale
Find fourth proportional to 37.21, 55.81 and 22
Similar ratio
Find fourth proportional to 54.32, 81.47 and 31.50
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.