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Finding the Fourth Proportional to 805.65, 1,208.55 and 285.60

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Solution

The fourth proportional to 805.65, 1,208.55 and 285.60 is: 428.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.65 : 1,208.55 = 285.60 : x
  2. Step 2: Convert to fraction form
    805.65/1,208.55 = 285.60/x
  3. Step 3: Cross multiply
    805.65x = 1,208.55 × 285.60
  4. Step 4: Simplify right side
    805.65x = 345,161.88
  5. Step 5: Solve for x
    x = 345,161.88/805.65
  6. Step 6: Final answer
    x = 428.43

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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.