Home / 272.40-408.36-128.28

Finding the Fourth Proportional to 272.40, 408.36 and 128.28

Calculator

Solution

The fourth proportional to 272.40, 408.36 and 128.28 is: 192.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    272.40 : 408.36 = 128.28 : x
  2. Step 2: Convert to fraction form
    272.40/408.36 = 128.28/x
  3. Step 3: Cross multiply
    272.40x = 408.36 × 128.28
  4. Step 4: Simplify right side
    272.40x = 52,384.42
  5. Step 5: Solve for x
    x = 52,384.42/272.40
  6. Step 6: Final answer
    x = 192.31

Related Problems

Find fourth proportional to 136.20, 204.18 and 64.14
Half scale
Find fourth proportional to 544.80, 816.72 and 256.56
Double scale
Find fourth proportional to 273.40, 409.86 and 129.28
Similar ratio
Find fourth proportional to 408.60, 612.54 and 192.42
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.