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Finding the Fourth Proportional to 805.11, 1,207.78 and 257.22

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Solution

The fourth proportional to 805.11, 1,207.78 and 257.22 is: 385.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.11 : 1,207.78 = 257.22 : x
  2. Step 2: Convert to fraction form
    805.11/1,207.78 = 257.22/x
  3. Step 3: Cross multiply
    805.11x = 1,207.78 × 257.22
  4. Step 4: Simplify right side
    805.11x = 310,664.53
  5. Step 5: Solve for x
    x = 310,664.53/805.11
  6. Step 6: Final answer
    x = 385.87

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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.