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Finding the Fourth Proportional to 318.72, 440.32 and 290.56

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Solution

The fourth proportional to 318.72, 440.32 and 290.56 is: 401.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.72 : 440.32 = 290.56 : x
  2. Step 2: Convert to fraction form
    318.72/440.32 = 290.56/x
  3. Step 3: Cross multiply
    318.72x = 440.32 × 290.56
  4. Step 4: Simplify right side
    318.72x = 127,939.38
  5. Step 5: Solve for x
    x = 127,939.38/318.72
  6. Step 6: Final answer
    x = 401.42

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.