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Finding the Fourth Proportional to 805.56, 1,208.36 and 285.57

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Solution

The fourth proportional to 805.56, 1,208.36 and 285.57 is: 428.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.56 : 1,208.36 = 285.57 : x
  2. Step 2: Convert to fraction form
    805.56/1,208.36 = 285.57/x
  3. Step 3: Cross multiply
    805.56x = 1,208.36 × 285.57
  4. Step 4: Simplify right side
    805.56x = 345,069.94
  5. Step 5: Solve for x
    x = 345,069.94/805.56
  6. Step 6: Final answer
    x = 428.36

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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.