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Finding the Fourth Proportional to 365.12, 545.20 and 287.20

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Solution

The fourth proportional to 365.12, 545.20 and 287.20 is: 428.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    365.12 : 545.20 = 287.20 : x
  2. Step 2: Convert to fraction form
    365.12/545.20 = 287.20/x
  3. Step 3: Cross multiply
    365.12x = 545.20 × 287.20
  4. Step 4: Simplify right side
    365.12x = 156,581.44
  5. Step 5: Solve for x
    x = 156,581.44/365.12
  6. Step 6: Final answer
    x = 428.85

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.