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Finding the Fourth Proportional to 505.20, 697.05 and 318.69

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Solution

The fourth proportional to 505.20, 697.05 and 318.69 is: 439.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.20 : 697.05 = 318.69 : x
  2. Step 2: Convert to fraction form
    505.20/697.05 = 318.69/x
  3. Step 3: Cross multiply
    505.20x = 697.05 × 318.69
  4. Step 4: Simplify right side
    505.20x = 222,142.86
  5. Step 5: Solve for x
    x = 222,142.86/505.20
  6. Step 6: Final answer
    x = 439.71

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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.