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Finding the Fourth Proportional to 645.89, 890.99 and 409.43

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Solution

The fourth proportional to 645.89, 890.99 and 409.43 is: 564.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.89 : 890.99 = 409.43 : x
  2. Step 2: Convert to fraction form
    645.89/890.99 = 409.43/x
  3. Step 3: Cross multiply
    645.89x = 890.99 × 409.43
  4. Step 4: Simplify right side
    645.89x = 364,798.04
  5. Step 5: Solve for x
    x = 364,798.04/645.89
  6. Step 6: Final answer
    x = 564.80

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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.