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Finding the Fourth Proportional to 505.31, 697.34 and 318.61

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Solution

The fourth proportional to 505.31, 697.34 and 318.61 is: 439.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    505.31 : 697.34 = 318.61 : x
  2. Step 2: Convert to fraction form
    505.31/697.34 = 318.61/x
  3. Step 3: Cross multiply
    505.31x = 697.34 × 318.61
  4. Step 4: Simplify right side
    505.31x = 222,179.50
  5. Step 5: Solve for x
    x = 222,179.50/505.31
  6. Step 6: Final answer
    x = 439.69

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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.