Home / 159.40-219.52-128.28

Finding the Fourth Proportional to 159.40, 219.52 and 128.28

Calculator

Solution

The fourth proportional to 159.40, 219.52 and 128.28 is: 176.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    159.40 : 219.52 = 128.28 : x
  2. Step 2: Convert to fraction form
    159.40/219.52 = 128.28/x
  3. Step 3: Cross multiply
    159.40x = 219.52 × 128.28
  4. Step 4: Simplify right side
    159.40x = 28,160.03
  5. Step 5: Solve for x
    x = 28,160.03/159.40
  6. Step 6: Final answer
    x = 176.66

Related Problems

Find fourth proportional to 79.70, 109.76 and 64.14
Half scale
Find fourth proportional to 318.80, 439.04 and 256.56
Double scale
Find fourth proportional to 160.40, 220.90 and 129.28
Similar ratio
Find fourth proportional to 239.10, 329.28 and 192.42
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.