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Finding the Fourth Proportional to 645.25, 890.67 and 402.91

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Solution

The fourth proportional to 645.25, 890.67 and 402.91 is: 556.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.25 : 890.67 = 402.91 : x
  2. Step 2: Convert to fraction form
    645.25/890.67 = 402.91/x
  3. Step 3: Cross multiply
    645.25x = 890.67 × 402.91
  4. Step 4: Simplify right side
    645.25x = 358,853.38
  5. Step 5: Solve for x
    x = 358,853.38/645.25
  6. Step 6: Final answer
    x = 556.15

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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.