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Finding the Fourth Proportional to 429.09, 643.62 and 185.79

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Solution

The fourth proportional to 429.09, 643.62 and 185.79 is: 278.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.09 : 643.62 = 185.79 : x
  2. Step 2: Convert to fraction form
    429.09/643.62 = 185.79/x
  3. Step 3: Cross multiply
    429.09x = 643.62 × 185.79
  4. Step 4: Simplify right side
    429.09x = 119,578.16
  5. Step 5: Solve for x
    x = 119,578.16/429.09
  6. Step 6: Final answer
    x = 278.68

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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.