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Finding the Fourth Proportional to 689.61, 1,034.42 and 485.09

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Solution

The fourth proportional to 689.61, 1,034.42 and 485.09 is: 727.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.61 : 1,034.42 = 485.09 : x
  2. Step 2: Convert to fraction form
    689.61/1,034.42 = 485.09/x
  3. Step 3: Cross multiply
    689.61x = 1,034.42 × 485.09
  4. Step 4: Simplify right side
    689.61x = 501,786.96
  5. Step 5: Solve for x
    x = 501,786.96/689.61
  6. Step 6: Final answer
    x = 727.64

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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.