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Finding the Fourth Proportional to 805.39, 1,208.02 and 318.45

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Solution

The fourth proportional to 805.39, 1,208.02 and 318.45 is: 477.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.39 : 1,208.02 = 318.45 : x
  2. Step 2: Convert to fraction form
    805.39/1,208.02 = 318.45/x
  3. Step 3: Cross multiply
    805.39x = 1,208.02 × 318.45
  4. Step 4: Simplify right side
    805.39x = 384,693.97
  5. Step 5: Solve for x
    x = 384,693.97/805.39
  6. Step 6: Final answer
    x = 477.65

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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.