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Finding the Fourth Proportional to 429.96, 645.30 and 285.78

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Solution

The fourth proportional to 429.96, 645.30 and 285.78 is: 428.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.96 : 645.30 = 285.78 : x
  2. Step 2: Convert to fraction form
    429.96/645.30 = 285.78/x
  3. Step 3: Cross multiply
    429.96x = 645.30 × 285.78
  4. Step 4: Simplify right side
    429.96x = 184,413.83
  5. Step 5: Solve for x
    x = 184,413.83/429.96
  6. Step 6: Final answer
    x = 428.91

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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.