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Finding the Fourth Proportional to 631.20, 871.20 and 409.77

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Solution

The fourth proportional to 631.20, 871.20 and 409.77 is: 565.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.20 : 871.20 = 409.77 : x
  2. Step 2: Convert to fraction form
    631.20/871.20 = 409.77/x
  3. Step 3: Cross multiply
    631.20x = 871.20 × 409.77
  4. Step 4: Simplify right side
    631.20x = 356,989.45
  5. Step 5: Solve for x
    x = 356,989.45/631.20
  6. Step 6: Final answer
    x = 565.57

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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.