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Finding the Fourth Proportional to 664.21, 994.55 and 429.31

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Solution

The fourth proportional to 664.21, 994.55 and 429.31 is: 642.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    664.21 : 994.55 = 429.31 : x
  2. Step 2: Convert to fraction form
    664.21/994.55 = 429.31/x
  3. Step 3: Cross multiply
    664.21x = 994.55 × 429.31
  4. Step 4: Simplify right side
    664.21x = 426,968.85
  5. Step 5: Solve for x
    x = 426,968.85/664.21
  6. Step 6: Final answer
    x = 642.82

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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.