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Finding the Fourth Proportional to 667.50, 921.15 and 405.47

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Solution

The fourth proportional to 667.50, 921.15 and 405.47 is: 559.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.50 : 921.15 = 405.47 : x
  2. Step 2: Convert to fraction form
    667.50/921.15 = 405.47/x
  3. Step 3: Cross multiply
    667.50x = 921.15 × 405.47
  4. Step 4: Simplify right side
    667.50x = 373,494.08
  5. Step 5: Solve for x
    x = 373,494.08/667.50
  6. Step 6: Final answer
    x = 559.54

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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.