Home / 149.72-206.42-128.92

Finding the Fourth Proportional to 149.72, 206.42 and 128.92

Calculator

Solution

The fourth proportional to 149.72, 206.42 and 128.92 is: 177.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    149.72 : 206.42 = 128.92 : x
  2. Step 2: Convert to fraction form
    149.72/206.42 = 128.92/x
  3. Step 3: Cross multiply
    149.72x = 206.42 × 128.92
  4. Step 4: Simplify right side
    149.72x = 26,611.67
  5. Step 5: Solve for x
    x = 26,611.67/149.72
  6. Step 6: Final answer
    x = 177.74

Related Problems

Find fourth proportional to 74.86, 103.21 and 64.46
Half scale
Find fourth proportional to 299.44, 412.84 and 257.84
Double scale
Find fourth proportional to 150.72, 207.80 and 129.92
Similar ratio
Find fourth proportional to 224.58, 309.63 and 193.38
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.