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Finding the Fourth Proportional to 415.20, 622.08 and 286.80

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Solution

The fourth proportional to 415.20, 622.08 and 286.80 is: 429.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    415.20 : 622.08 = 286.80 : x
  2. Step 2: Convert to fraction form
    415.20/622.08 = 286.80/x
  3. Step 3: Cross multiply
    415.20x = 622.08 × 286.80
  4. Step 4: Simplify right side
    415.20x = 178,412.54
  5. Step 5: Solve for x
    x = 178,412.54/415.20
  6. Step 6: Final answer
    x = 429.70

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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.