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Finding the Fourth Proportional to 429.43, 643.49 and 290.09

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Solution

The fourth proportional to 429.43, 643.49 and 290.09 is: 434.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.43 : 643.49 = 290.09 : x
  2. Step 2: Convert to fraction form
    429.43/643.49 = 290.09/x
  3. Step 3: Cross multiply
    429.43x = 643.49 × 290.09
  4. Step 4: Simplify right side
    429.43x = 186,670.01
  5. Step 5: Solve for x
    x = 186,670.01/429.43
  6. Step 6: Final answer
    x = 434.69

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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.