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Finding the Fourth Proportional to 806.20, 1,208.47 and 318.58

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Solution

The fourth proportional to 806.20, 1,208.47 and 318.58 is: 477.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    806.20 : 1,208.47 = 318.58 : x
  2. Step 2: Convert to fraction form
    806.20/1,208.47 = 318.58/x
  3. Step 3: Cross multiply
    806.20x = 1,208.47 × 318.58
  4. Step 4: Simplify right side
    806.20x = 384,994.37
  5. Step 5: Solve for x
    x = 384,994.37/806.20
  6. Step 6: Final answer
    x = 477.54

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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.