Home / 406.72-609.90-129

Finding the Fourth Proportional to 406.72, 609.90 and 129

Calculator

Solution

The fourth proportional to 406.72, 609.90 and 129 is: 193.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.72 : 609.90 = 129 : x
  2. Step 2: Convert to fraction form
    406.72/609.90 = 129/x
  3. Step 3: Cross multiply
    406.72x = 609.90 × 129
  4. Step 4: Simplify right side
    406.72x = 78,677.10
  5. Step 5: Solve for x
    x = 78,677.10/406.72
  6. Step 6: Final answer
    x = 193.44

Related Problems

Find fourth proportional to 203.36, 304.95 and 64.50
Half scale
Find fourth proportional to 813.44, 1,219.80 and 258
Double scale
Find fourth proportional to 407.72, 611.40 and 130
Similar ratio
Find fourth proportional to 610.08, 914.85 and 193.50
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.