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Finding the Fourth Proportional to 429.09, 643.15 and 281.13

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Solution

The fourth proportional to 429.09, 643.15 and 281.13 is: 421.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.09 : 643.15 = 281.13 : x
  2. Step 2: Convert to fraction form
    429.09/643.15 = 281.13/x
  3. Step 3: Cross multiply
    429.09x = 643.15 × 281.13
  4. Step 4: Simplify right side
    429.09x = 180,805.77
  5. Step 5: Solve for x
    x = 180,805.77/429.09
  6. Step 6: Final answer
    x = 421.37

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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.