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Finding the Fourth Proportional to 285.12, 428.40 and 269.28

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Solution

The fourth proportional to 285.12, 428.40 and 269.28 is: 404.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    285.12 : 428.40 = 269.28 : x
  2. Step 2: Convert to fraction form
    285.12/428.40 = 269.28/x
  3. Step 3: Cross multiply
    285.12x = 428.40 × 269.28
  4. Step 4: Simplify right side
    285.12x = 115,359.55
  5. Step 5: Solve for x
    x = 115,359.55/285.12
  6. Step 6: Final answer
    x = 404.60

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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.