Home / 141.39-212.20-90.12

Finding the Fourth Proportional to 141.39, 212.20 and 90.12

Calculator

Solution

The fourth proportional to 141.39, 212.20 and 90.12 is: 135.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    141.39 : 212.20 = 90.12 : x
  2. Step 2: Convert to fraction form
    141.39/212.20 = 90.12/x
  3. Step 3: Cross multiply
    141.39x = 212.20 × 90.12
  4. Step 4: Simplify right side
    141.39x = 19,123.24
  5. Step 5: Solve for x
    x = 19,123.24/141.39
  6. Step 6: Final answer
    x = 135.25

Related Problems

Find fourth proportional to 70.70, 106.10 and 45.06
Half scale
Find fourth proportional to 282.78, 424.40 and 180.24
Double scale
Find fourth proportional to 142.39, 213.70 and 91.12
Similar ratio
Find fourth proportional to 212.09, 318.30 and 135.18
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.