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Finding the Fourth Proportional to 505.82, 697.68 and 309.42

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Solution

The fourth proportional to 505.82, 697.68 and 309.42 is: 426.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.82 : 697.68 = 309.42 : x
  2. Step 2: Convert to fraction form
    505.82/697.68 = 309.42/x
  3. Step 3: Cross multiply
    505.82x = 697.68 × 309.42
  4. Step 4: Simplify right side
    505.82x = 215,874.60
  5. Step 5: Solve for x
    x = 215,874.60/505.82
  6. Step 6: Final answer
    x = 426.79

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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.