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Finding the Fourth Proportional to 418.95, 628.38 and 213.65

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Solution

The fourth proportional to 418.95, 628.38 and 213.65 is: 320.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    418.95 : 628.38 = 213.65 : x
  2. Step 2: Convert to fraction form
    418.95/628.38 = 213.65/x
  3. Step 3: Cross multiply
    418.95x = 628.38 × 213.65
  4. Step 4: Simplify right side
    418.95x = 134,253.39
  5. Step 5: Solve for x
    x = 134,253.39/418.95
  6. Step 6: Final answer
    x = 320.45

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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.