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Finding the Fourth Proportional to 667.51, 921.13 and 387.55

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Solution

The fourth proportional to 667.51, 921.13 and 387.55 is: 534.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.51 : 921.13 = 387.55 : x
  2. Step 2: Convert to fraction form
    667.51/921.13 = 387.55/x
  3. Step 3: Cross multiply
    667.51x = 921.13 × 387.55
  4. Step 4: Simplify right side
    667.51x = 356,983.93
  5. Step 5: Solve for x
    x = 356,983.93/667.51
  6. Step 6: Final answer
    x = 534.80

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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.