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Finding the Fourth Proportional to 805.67, 1,208.72 and 285.80

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Solution

The fourth proportional to 805.67, 1,208.72 and 285.80 is: 428.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.67 : 1,208.72 = 285.80 : x
  2. Step 2: Convert to fraction form
    805.67/1,208.72 = 285.80/x
  3. Step 3: Cross multiply
    805.67x = 1,208.72 × 285.80
  4. Step 4: Simplify right side
    805.67x = 345,444.70
  5. Step 5: Solve for x
    x = 345,444.70/805.67
  6. Step 6: Final answer
    x = 428.77

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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.