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Finding the Fourth Proportional to 685.62, 1,028.79 and 442.62

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Solution

The fourth proportional to 685.62, 1,028.79 and 442.62 is: 664.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.62 : 1,028.79 = 442.62 : x
  2. Step 2: Convert to fraction form
    685.62/1,028.79 = 442.62/x
  3. Step 3: Cross multiply
    685.62x = 1,028.79 × 442.62
  4. Step 4: Simplify right side
    685.62x = 455,363.03
  5. Step 5: Solve for x
    x = 455,363.03/685.62
  6. Step 6: Final answer
    x = 664.16

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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.