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Finding the Fourth Proportional to 645.47, 890.42 and 409.02

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Solution

The fourth proportional to 645.47, 890.42 and 409.02 is: 564.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.47 : 890.42 = 409.02 : x
  2. Step 2: Convert to fraction form
    645.47/890.42 = 409.02/x
  3. Step 3: Cross multiply
    645.47x = 890.42 × 409.02
  4. Step 4: Simplify right side
    645.47x = 364,197.54
  5. Step 5: Solve for x
    x = 364,197.54/645.47
  6. Step 6: Final answer
    x = 564.24

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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.