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Finding the Fourth Proportional to 685.91, 1,028.82 and 339.16

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Solution

The fourth proportional to 685.91, 1,028.82 and 339.16 is: 508.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.91 : 1,028.82 = 339.16 : x
  2. Step 2: Convert to fraction form
    685.91/1,028.82 = 339.16/x
  3. Step 3: Cross multiply
    685.91x = 1,028.82 × 339.16
  4. Step 4: Simplify right side
    685.91x = 348,934.59
  5. Step 5: Solve for x
    x = 348,934.59/685.91
  6. Step 6: Final answer
    x = 508.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.