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Finding the Fourth Proportional to 691.49, 954.36 and 396.78

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Solution

The fourth proportional to 691.49, 954.36 and 396.78 is: 547.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.49 : 954.36 = 396.78 : x
  2. Step 2: Convert to fraction form
    691.49/954.36 = 396.78/x
  3. Step 3: Cross multiply
    691.49x = 954.36 × 396.78
  4. Step 4: Simplify right side
    691.49x = 378,670.96
  5. Step 5: Solve for x
    x = 378,670.96/691.49
  6. Step 6: Final answer
    x = 547.62

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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.