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Finding the Fourth Proportional to 418.12, 626.78 and 281.21

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Solution

The fourth proportional to 418.12, 626.78 and 281.21 is: 421.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.12 : 626.78 = 281.21 : x
  2. Step 2: Convert to fraction form
    418.12/626.78 = 281.21/x
  3. Step 3: Cross multiply
    418.12x = 626.78 × 281.21
  4. Step 4: Simplify right side
    418.12x = 176,254.37
  5. Step 5: Solve for x
    x = 176,254.37/418.12
  6. Step 6: Final answer
    x = 421.54

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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.