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Finding the Fourth Proportional to 414.15, 621.39 and 208.78

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Solution

The fourth proportional to 414.15, 621.39 and 208.78 is: 313.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    414.15 : 621.39 = 208.78 : x
  2. Step 2: Convert to fraction form
    414.15/621.39 = 208.78/x
  3. Step 3: Cross multiply
    414.15x = 621.39 × 208.78
  4. Step 4: Simplify right side
    414.15x = 129,733.03
  5. Step 5: Solve for x
    x = 129,733.03/414.15
  6. Step 6: Final answer
    x = 313.25

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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.