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Finding the Fourth Proportional to 685.12, 1,027.76 and 631.68

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Solution

The fourth proportional to 685.12, 1,027.76 and 631.68 is: 947.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.12 : 1,027.76 = 631.68 : x
  2. Step 2: Convert to fraction form
    685.12/1,027.76 = 631.68/x
  3. Step 3: Cross multiply
    685.12x = 1,027.76 × 631.68
  4. Step 4: Simplify right side
    685.12x = 649,215.44
  5. Step 5: Solve for x
    x = 649,215.44/685.12
  6. Step 6: Final answer
    x = 947.59

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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.