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Finding the Fourth Proportional to 414.79, 621.88 and 209.21

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Solution

The fourth proportional to 414.79, 621.88 and 209.21 is: 313.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    414.79 : 621.88 = 209.21 : x
  2. Step 2: Convert to fraction form
    414.79/621.88 = 209.21/x
  3. Step 3: Cross multiply
    414.79x = 621.88 × 209.21
  4. Step 4: Simplify right side
    414.79x = 130,103.51
  5. Step 5: Solve for x
    x = 130,103.51/414.79
  6. Step 6: Final answer
    x = 313.66

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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.