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Finding the Fourth Proportional to 318.91, 478.42 and 136.21

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Solution

The fourth proportional to 318.91, 478.42 and 136.21 is: 204.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.91 : 478.42 = 136.21 : x
  2. Step 2: Convert to fraction form
    318.91/478.42 = 136.21/x
  3. Step 3: Cross multiply
    318.91x = 478.42 × 136.21
  4. Step 4: Simplify right side
    318.91x = 65,164.05
  5. Step 5: Solve for x
    x = 65,164.05/318.91
  6. Step 6: Final answer
    x = 204.34

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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.