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Finding the Fourth Proportional to 451.87, 678.15 and 208.42

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Solution

The fourth proportional to 451.87, 678.15 and 208.42 is: 312.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.87 : 678.15 = 208.42 : x
  2. Step 2: Convert to fraction form
    451.87/678.15 = 208.42/x
  3. Step 3: Cross multiply
    451.87x = 678.15 × 208.42
  4. Step 4: Simplify right side
    451.87x = 141,338.33
  5. Step 5: Solve for x
    x = 141,338.33/451.87
  6. Step 6: Final answer
    x = 312.79

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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.