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Finding the Fourth Proportional to 645.06, 890.28 and 409.20

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Solution

The fourth proportional to 645.06, 890.28 and 409.20 is: 564.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.06 : 890.28 = 409.20 : x
  2. Step 2: Convert to fraction form
    645.06/890.28 = 409.20/x
  3. Step 3: Cross multiply
    645.06x = 890.28 × 409.20
  4. Step 4: Simplify right side
    645.06x = 364,302.58
  5. Step 5: Solve for x
    x = 364,302.58/645.06
  6. Step 6: Final answer
    x = 564.76

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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.