Home / 203.11-304.39-81.21

Finding the Fourth Proportional to 203.11, 304.39 and 81.21

Calculator

Solution

The fourth proportional to 203.11, 304.39 and 81.21 is: 121.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    203.11 : 304.39 = 81.21 : x
  2. Step 2: Convert to fraction form
    203.11/304.39 = 81.21/x
  3. Step 3: Cross multiply
    203.11x = 304.39 × 81.21
  4. Step 4: Simplify right side
    203.11x = 24,719.51
  5. Step 5: Solve for x
    x = 24,719.51/203.11
  6. Step 6: Final answer
    x = 121.71

Related Problems

Find fourth proportional to 101.56, 152.20 and 40.61
Half scale
Find fourth proportional to 406.22, 608.78 and 162.42
Double scale
Find fourth proportional to 204.11, 305.89 and 82.21
Similar ratio
Find fourth proportional to 304.67, 456.59 and 121.82
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.