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Finding the Fourth Proportional to 871.76, 1,306.38 and 438.32

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Solution

The fourth proportional to 871.76, 1,306.38 and 438.32 is: 656.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.76 : 1,306.38 = 438.32 : x
  2. Step 2: Convert to fraction form
    871.76/1,306.38 = 438.32/x
  3. Step 3: Cross multiply
    871.76x = 1,306.38 × 438.32
  4. Step 4: Simplify right side
    871.76x = 572,612.48
  5. Step 5: Solve for x
    x = 572,612.48/871.76
  6. Step 6: Final answer
    x = 656.85

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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.