Home / 425.10-638.20-220.08

Finding the Fourth Proportional to 425.10, 638.20 and 220.08

Calculator

Solution

The fourth proportional to 425.10, 638.20 and 220.08 is: 330.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.10 : 638.20 = 220.08 : x
  2. Step 2: Convert to fraction form
    425.10/638.20 = 220.08/x
  3. Step 3: Cross multiply
    425.10x = 638.20 × 220.08
  4. Step 4: Simplify right side
    425.10x = 140,455.06
  5. Step 5: Solve for x
    x = 140,455.06/425.10
  6. Step 6: Final answer
    x = 330.40

Related Problems

Find fourth proportional to 212.55, 319.10 and 110.04
Half scale
Find fourth proportional to 850.20, 1,276.40 and 440.16
Double scale
Find fourth proportional to 426.10, 639.70 and 221.08
Similar ratio
Find fourth proportional to 637.65, 957.30 and 330.12
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.