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Finding the Fourth Proportional to 414.78, 621.80 and 209.06

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Solution

The fourth proportional to 414.78, 621.80 and 209.06 is: 313.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    414.78 : 621.80 = 209.06 : x
  2. Step 2: Convert to fraction form
    414.78/621.80 = 209.06/x
  3. Step 3: Cross multiply
    414.78x = 621.80 × 209.06
  4. Step 4: Simplify right side
    414.78x = 129,993.51
  5. Step 5: Solve for x
    x = 129,993.51/414.78
  6. Step 6: Final answer
    x = 313.40

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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.