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Finding the Fourth Proportional to 667.55, 921.17 and 387.76

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Solution

The fourth proportional to 667.55, 921.17 and 387.76 is: 535.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.55 : 921.17 = 387.76 : x
  2. Step 2: Convert to fraction form
    667.55/921.17 = 387.76/x
  3. Step 3: Cross multiply
    667.55x = 921.17 × 387.76
  4. Step 4: Simplify right side
    667.55x = 357,192.88
  5. Step 5: Solve for x
    x = 357,192.88/667.55
  6. Step 6: Final answer
    x = 535.08

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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.