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Finding the Fourth Proportional to 414.21, 621.40 and 121.72

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Solution

The fourth proportional to 414.21, 621.40 and 121.72 is: 182.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    414.21 : 621.40 = 121.72 : x
  2. Step 2: Convert to fraction form
    414.21/621.40 = 121.72/x
  3. Step 3: Cross multiply
    414.21x = 621.40 × 121.72
  4. Step 4: Simplify right side
    414.21x = 75,633.70
  5. Step 5: Solve for x
    x = 75,633.70/414.21
  6. Step 6: Final answer
    x = 182.60

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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.