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Finding the Fourth Proportional to 645.27, 890.13 and 396.64

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Solution

The fourth proportional to 645.27, 890.13 and 396.64 is: 547.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.27 : 890.13 = 396.64 : x
  2. Step 2: Convert to fraction form
    645.27/890.13 = 396.64/x
  3. Step 3: Cross multiply
    645.27x = 890.13 × 396.64
  4. Step 4: Simplify right side
    645.27x = 353,061.16
  5. Step 5: Solve for x
    x = 353,061.16/645.27
  6. Step 6: Final answer
    x = 547.16

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.