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Finding the Fourth Proportional to 426.72, 639.63 and 381.16

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Solution

The fourth proportional to 426.72, 639.63 and 381.16 is: 571.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.72 : 639.63 = 381.16 : x
  2. Step 2: Convert to fraction form
    426.72/639.63 = 381.16/x
  3. Step 3: Cross multiply
    426.72x = 639.63 × 381.16
  4. Step 4: Simplify right side
    426.72x = 243,801.37
  5. Step 5: Solve for x
    x = 243,801.37/426.72
  6. Step 6: Final answer
    x = 571.34

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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.