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Finding the Fourth Proportional to 427.95, 641.81 and 211.47

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Solution

The fourth proportional to 427.95, 641.81 and 211.47 is: 317.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.95 : 641.81 = 211.47 : x
  2. Step 2: Convert to fraction form
    427.95/641.81 = 211.47/x
  3. Step 3: Cross multiply
    427.95x = 641.81 × 211.47
  4. Step 4: Simplify right side
    427.95x = 135,723.56
  5. Step 5: Solve for x
    x = 135,723.56/427.95
  6. Step 6: Final answer
    x = 317.15

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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.