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Finding the Fourth Proportional to 320.42, 480.68 and 137.72

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Solution

The fourth proportional to 320.42, 480.68 and 137.72 is: 206.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    320.42 : 480.68 = 137.72 : x
  2. Step 2: Convert to fraction form
    320.42/480.68 = 137.72/x
  3. Step 3: Cross multiply
    320.42x = 480.68 × 137.72
  4. Step 4: Simplify right side
    320.42x = 66,196.16
  5. Step 5: Solve for x
    x = 66,196.16/320.42
  6. Step 6: Final answer
    x = 206.60

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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.