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Finding the Fourth Proportional to 645.65, 890.63 and 557.49

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Solution

The fourth proportional to 645.65, 890.63 and 557.49 is: 769.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.65 : 890.63 = 557.49 : x
  2. Step 2: Convert to fraction form
    645.65/890.63 = 557.49/x
  3. Step 3: Cross multiply
    645.65x = 890.63 × 557.49
  4. Step 4: Simplify right side
    645.65x = 496,517.32
  5. Step 5: Solve for x
    x = 496,517.32/645.65
  6. Step 6: Final answer
    x = 769.03

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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.