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Finding the Fourth Proportional to 415.20, 622.80 and 397.20

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Solution

The fourth proportional to 415.20, 622.80 and 397.20 is: 595.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.20 : 622.80 = 397.20 : x
  2. Step 2: Convert to fraction form
    415.20/622.80 = 397.20/x
  3. Step 3: Cross multiply
    415.20x = 622.80 × 397.20
  4. Step 4: Simplify right side
    415.20x = 247,376.16
  5. Step 5: Solve for x
    x = 247,376.16/415.20
  6. Step 6: Final answer
    x = 595.80

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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.