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Finding the Fourth Proportional to 631.16, 871.26 and 491.66

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Solution

The fourth proportional to 631.16, 871.26 and 491.66 is: 678.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.16 : 871.26 = 491.66 : x
  2. Step 2: Convert to fraction form
    631.16/871.26 = 491.66/x
  3. Step 3: Cross multiply
    631.16x = 871.26 × 491.66
  4. Step 4: Simplify right side
    631.16x = 428,363.69
  5. Step 5: Solve for x
    x = 428,363.69/631.16
  6. Step 6: Final answer
    x = 678.69

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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.