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Finding the Fourth Proportional to 428.14, 638.58 and 415.13

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Solution

The fourth proportional to 428.14, 638.58 and 415.13 is: 619.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.14 : 638.58 = 415.13 : x
  2. Step 2: Convert to fraction form
    428.14/638.58 = 415.13/x
  3. Step 3: Cross multiply
    428.14x = 638.58 × 415.13
  4. Step 4: Simplify right side
    428.14x = 265,092.08
  5. Step 5: Solve for x
    x = 265,092.08/428.14
  6. Step 6: Final answer
    x = 619.18

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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.