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Finding the Fourth Proportional to 656.80, 906.51 and 421.09

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Solution

The fourth proportional to 656.80, 906.51 and 421.09 is: 581.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    656.80 : 906.51 = 421.09 : x
  2. Step 2: Convert to fraction form
    656.80/906.51 = 421.09/x
  3. Step 3: Cross multiply
    656.80x = 906.51 × 421.09
  4. Step 4: Simplify right side
    656.80x = 381,722.30
  5. Step 5: Solve for x
    x = 381,722.30/656.80
  6. Step 6: Final answer
    x = 581.18

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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.